I'm into this audio thing since 1996 when i was around 22. I had an amplifier ONKYO Integra MA 1000X back in 2002, i used it for over 4 years and then sold it out n it was all so fine. Watched this full video after a very long time. Sir these Japanese amps will make yoy fall in love with them and the way you worked is really so interesting with all the details you hv been Sharing. Really amazing sir. Lots of love n respect from Pakistan.
Thanks for this Tony. Some excellent sharing of hints and tips with justification why you do it that way. For me the takeaways were: (i) Use a dummy input load prior to adjusting dc offset, (ii) Don't use D5 on carbon tracks, (iii) Use white vinegar for removal of corrosion, (iv) Clip before soldering (I've always done the opposite).
Tony... Very, very informative... And I genuinely appreciate your videos. Finally, I know where to begin correcting my naïve deoxit madness on my Pioneer SA-8500 Pair.
Tony, thanks for great and invaluable videos. The insight and knowledge you share is 2nd to none and something i would expect to pay for. Please keep them coming. Even though i am no Engineer I now feel able to tackle some of basic maintenance that these great works of art require.
At 13:05 you stated that there was no Digi-key, no Mouser back in the 70's. Actually, there were both - Mouser started in 1964, and Digi-key started in 1972. They put out heavy thick free catalogs, and you would either get on the phone and call in your order, or send them an order in a letter. I always just called Digi-key, they were always friendly and fun to speak with. Both have been online for a long time, with easy-to-use online catalogs and ordering.
It be noted that scratchy pots may also be caused / exacerbated by surrounding coupling capacitors with excessive leakage current putting DC on the wiper, so always keep this possibility in mind as well. This particularly applies to lower-voltage parts and will be a function of capacitor series and age, given that electrolyte composition has changed multiple times over the years and long-time chemical stability may vary.
Great video and some good tips. I have a Kenwood KA-7100 that I use all the time but it too has a scratchy volume control among other minor issues that will require some troubleshooting. I also do some refurbs as a hobby so have decent equipment. I'll be using some of your tips on my Kenwood especially the tips on cleaning the pots.
Discovered the hard way while repairing a Moog synthesiser that those carbon track wafers are really easy to destroy with the wrong chemicals. Luckily, CTS pots still use the same wafer design as they did in 1981, so I was able to buy some new pots (with a different shaft), swap over the wafers and lubricate them like new. Sharp side cutters are brilliant for getting under the bent tabs to get them open!
Thank you Tony for sharing your tips. These Deoxit sprays are not available everywhere, but there's always some decent manufacturer doing something equivalent nearby... You should also explain why these volume pots are so difficult to replace with their intermediary output designed for loudness circuitry. Most of these are nearly impossible to replace, and when you manage to find some equivalent, they generally come in expensive order made monsters. So everytime you intervene around these, it's never such simple operation! I also remember the pre internet period, when you could find shops selling components in nearly all big cities, but they generally sold basic crap and kits, and rarely or never any Japanese transistor. Here in Europe, even big retailers avoided them because of duty taxes, and you have to know the right address in a crappy suburb to find "the Vietnamese" selling marvels in his garage... It's now far more easy to find some Chinese (fake?) components than real stuff in dedicated internet shops (Germans are particularly efficient about audio components, UK sellers are now unavailable...). It could be very interesting to compare our typical command list!
Thanks for going over your two-stage cleaning process and your recommendations on chemicals. (Now of course the price will go up on all the brands you named, more's the pity)
In the 1960's the Pioneer SA series were given high praise from leading audio magazines and considered one of the best sounding amps that money could buy.
11:00 Clipping the lead off before soldering is the way we were trained when working on military circuit boards. No more than pad height on clipped length, so like a little triangle. No copper showing when looking under a binocular microscope.Probably too fussy for consumer grade equipment, granted.
I remember once having to get a replacement rectifier diode for a Dyanco 120 Power Amp in the early 70's. The house didn't have the stock part so they talked me into buying a 4-pack of these "shiny silver" power rectifier diodes for about $10.00(!). I was able to obtain a closer match diode at a local Radio Shack for under 1.00. I still have those "space age" silver power rectifiers. I use them for lab work. So at least I got my $$ worth off of that adventure.
Hi, I always learn so much with your videos, if you allow me the observation, I think that plastic at the end of the potentiometer rotates 3 or 4 degrees in relation to the shaft and allows to correct the balance between the two chanel's when the balance potentiometer is at center and there's some mismatch in volume, I have a pioneer SA3000 integrated from 1979 and I was about to replace the potentiometer when I found this and solved the problem
Thanks Tony for the info on the use of fader lube. I switched over to it because it made more sense. What is a carbon track pot but a fader! Great vid as always.
Very nice !! I am hoping to be able to determine the values of the multi turn pots so I can replace the ones in my SX-737 when I work on it soon. I am going to print the schematics.. hope they either tell me or something can be read from the originals. I think it's a great idea to upgrade those !
Yes there is much misinformation about which cleaners to use. I'm using fader for pots and the 260d grease when I can take them apart. For metal to metal switches it's d100 followed by shield. Since I still live in CA I can buy syringes, over the counter, (or not shower and get them free from the state, lol) and use them when I need precision.
I've had a 7500 and a 7500 II. They both sound good, but the 7500 is sooooo much easier to work on and just plain laid out better. (Even though it's 5wpc less than the II version, I prefer the 7500.)
This is so weird... I use exactly the same amp for exactly the same purpose as you. My dad bought it for me many years ago and I've used it ever since. These retro amps seem to be becoming desirable of late. I just think it's a nice sounding amp.
I think you must be about the only person in the world who has an SA-7500 for a computer amp!!! (BTW my computer amp is a NAD 3020, not quite the same vintage as your beautiful 7500 but gets the job done)
I use a fully restored kenwood ka-701 (it was a basket case when I got it and hence was a cheap purchase, knowledge is power) that replaced a refurbished ka-7100 (the 701 has a lower signal to noise and it's noticeable with digital inputs). Very quiet 1980 vintage amp. It's runs off of a claro halo sound card with rca outs and powers a pair of klipsch fortes and some fostex th900s. Great sound and it's used for digital music and web vids like this one. It also looks great on top of my computer desk. More people should do this since these are great headphone amps (better than new amp on a chip amps) just pick your poison pioneer, marantz, yamaha, kenwood, sansui etc.
I have a Sansui AU-5500 that I use for my computer amplifier into a set of small speakers and a powered sub hooked to the preamp out jack. Sounds is amazing.
It's connected to a pair of Energy Point-One-E bookshelf speakers. It sounds great with music, and is extremely clear when listening to voice. It also has a really nice headphone output that gives a noticeable improvement over the computer's headphone output. Thanks for the comment!
I'm still using a "modified" Sony TA2000f as my main preamp / control center. It's basically the Sony version of this. It's got a noise issue in its main phono stage, but I don't use it. I use a newer external phono stage.
Thanks for your education, I am learning a lot ! DC Offset. I've noticed your concern about this. I have enjoyed recording since '75. And have noticed some equipment (mics n mixers) introduce DC offset to the waveform. This has become very common on the net. It is very hard to remove post prod'. An adjust for DC offset on record checkbox on software is good if effective. Some channels on ut are severe showing clipping on the upper or lower half of the waveform ! I have not checked your channel (yet) : ) I am not sure if it will be passed on to the amp. Should I worry ?
Great explanation and thanks for posting this. In my 60's and as a career electronics tech I love this stuff. One question regarding the tone board drivers; You stated the original PNP as 2SA725 and 726. You did not mention the original complementary NPN number. My NTE catalog is outdated and has no listing for replacements, KSA992 and KSC1845. It however shows the PNP replacement as NTE234 but without the original NPN number cannot cross reference. Could you provide? Thanks again.
That spray-in stuff manufacturer that starts with a "C" and ends with "aig" actually offers an attachment with a cut off syringe needle at the end. Overpriced, of course, but very handy!
Those new cans are terrible. I've had the had the hinged area of the yellow "fire hose" leak on me more than once, which will keep my hand from corroding, but does nothing for the switch I'm trying to spray. A lot of product is wasted. The yellow fire hose also doesn't fit in the opening of many controls because of the diameter, but of course you can buy the overpriced needle attachment ;)
In my opinion, it is extremely overpriced over here in the states as well. It is a good product, but I think it is a waste to use it for the cleaning process. That's why I use an inexpensive cleaner, such as that CRC product (there are many brands that all contain the same product) for the cleaning process and then just the smallest amount of expensive stuff as a protectant/lubricant. A can of the expensive product lasts a very long time, when used this way. Also, I can't stand the "new" container that caig uses with the huge yellow "fire hose" on the nozzle. If you look around, you can still buy the can with the standard nozzle that has adjustable output and can accept the standard red extension straw that comes with every other product. I see no advantage to the new container, other than wasting product and making you have to buy a new can sooner. I also think the overpriced needle adapter for the new can is not as good as the old design. Thank you for the comment!
Okay, I'm paying special attention to this one as my SA 7500 has tone control problems. When I turn on the tone control one channel drops a lot in volume.
So where I am (Philippines) Deoxit cost $50 per can. Do anybody know of a less expensive but equivalent cleaner available? Thanks in advance. I have to mention how incredibly valuable these videos are to me as a non-educated diyer. Thank you so much for the Pioneer videos, please make more of equally high standards and keep up the great work and channel. I just bought an SA-706 but after seeing this video I I think I’ll sell it and find a 7500 because of this and your other documentation.
Hi xraytonyb. Thank you for this video. Good job. I have a question about how you have placed VR2 in the PCB. The question is: Why this VR is placed just the opposite of VR1?. Looking the scheme, it looks that both positions must be the same in order to obtain the same resistence value when screws are turned to left.
Great explanation!I have a cracking noise from my equalizer amp (I have a SA-5500ii) and I guess have to replace the 2SA725 with the KSC992FBU. Would you recommend to replace the 2SC1312 too? (perhaps with a KSC1845FTA?)
Thanks Tony, You realize of course that we are all going to run out and get the Dexoit F100! :) I have a question, why did you remove the pre jumpers and install those terminators (5.1k) to set the offset? I have never done that before.
Any ideas of cleaning off circuit boards which have been saturated with deoxit cleaner? There was a product called Electro Wash, but have not seen it in years.
@@lloydparks4974 Thanks, that is exactly what I was looking for. $20 for 16 oz. on Amazon for the aerosol can, or $17 for the 1 liter bottle. I was thinking of using an extra waterpik dental cleaning device as a mini pressure washer. May or may not be practical, will have to try it.
No! "Dielectric" means insulating, putting it ito a potentiometer will alter its characteristics drastically or render it useless all together. Greasing up a pot, you don't want to introduce anything that would or could change the resistance between the wiper and the resistor element.
Woah, that looks increadibly similar to my amp, a Unicef Model TA-5300. The only thing is that I have the only known amp of that model, and even brand, so I'm eager to find any info on it. Do you know if Pioneer would have sold an amp like this or in this series under a different name, or sell the design to a other company? Any help at all will be massively appreciated.
I know that Pioneer marketed products under several other names, such as Centrex and sonic (maybe sonics). Most of the non-Pioneer branded gear was at least slightly different from the actual Pioneer-named products. That being said, I wouldn't be surprised if your unit was made or at least licensed by Pioneer. Thanks for the question!
Hi Tony! Thanks for this; interesting stuff, especially on snipping before soldering. One observation - when you were cleaning the flux, you applied alcohol and brushed the area, and I thought you might use a paper towel or something and absorb all that diluted flux, and then repeat the performance for even more cleaning, but it looks like you sorta left it there. My theory is that what you mostly accomplished was just diluting it and flowing it into a thin layer, rather than removing it. Does that make sense?
I usually don't wipe the flux with a paper towel because it tends to make the board sticky and the towel sticks to the flux and makes it look bad. The flux is the non-corrosive type and doesn't hurt if it's there. Many times, the boards have flux on them from the factory, but the heat from the soldering process makes it flow out smooth and shiny. If you've ever seen PC boards with a hazy white film on them, it's because that flux has gotten wet from contact cleaner or someone tried to wipe the board down with a rag soaked in alcohol. Using a brush or cotton swab soaked with anhydrous alcohol (no water content) will clean up most of the flux and let the remainder flow out into a shiny finish. You can scrub all of the flux off of the board, but it can be a lot of work, as the more you wipe it, the more it just spreads around and reconstitutes the flux around it. I guess there is no right or wrong way to do it, this is just the method i usually use. Thanks for the comment!
Thanks for a great video Tony. I've always wanted to know what dc offset and setting the bias was for. Is it possible to measure directly at the speaker outputs for adjusting dc offset?
Hello, I wanted to ask if there is a dcoffset, and there is a protection circuit, the relays do not click and there is no sound, what to focus on, please look for a bug, thank you for any comments
I also have 7500 and since I've had it, the stereo setting has not worked. It only plays from the right channel. I have to keep the amp in Mono to get sounds from both speakers. Any chance you can help me with this?
a stackable pot like lego would be nice. want a 100k lin coaxial with a hollow shaft, 20k log stereo, 10k lin and a switch at the back, just stack the modules as needed.
35:35 It is better to build this procedure on an analog tester (arrows). It's proven and useful, bro! After all, you have them!) Your power supply capacitors are terrible. You need to put Nippon Chemicon, only them! Thanks for the topic and excuse my English!)
I'm guessing KSA992, but there may be other options like the KSA1015 and KSA733. dlucy over at Audiokarma made a flowchart, you may want to take a look at that: www.audiokarma.org/forums/index.php?threads/transistor-substitutions.688515/page-7#post-11865547
How is it you came up with Robbie the robot as your channels emblem? (I'm sure it's been asked many times before but I've never noticed it in any of your videos) Gort
Surgical spirit is primarily alcohol. I don't know if it might desolve the adhesive that bonds the carbon to the wafer. If the pot still works you might just need to add something like the Fader Lube Surgical spirit often contains other chemicals which may or may not be ok. They might leave residue.
Well you could get the grease in there just use some grease on a thin piece of card just work it in. you can make your own contact cleaner 70% mineral spirits/white spirit, 30% isopropanol 99% 10% mineral oil WD-40 mix together put in a syringe with a blunt needle no spraying is needed you could substitute the isopropyl for acetone if using on metal contacts only.
I have worked and played with electronics for many years. This video actually taught me several things I never knew. This was AWSOME!
I'm into this audio thing since 1996 when i was around 22. I had an amplifier ONKYO Integra MA 1000X back in 2002, i used it for over 4 years and then sold it out n it was all so fine. Watched this full video after a very long time. Sir these Japanese amps will make yoy fall in love with them and the way you worked is really so interesting with all the details you hv been Sharing. Really amazing sir.
Lots of love n respect from Pakistan.
That's a beauty, there's something so elegant about these vintage pieces.
Thanks for this Tony. Some excellent sharing of hints and tips with justification why you do it that way. For me the takeaways were: (i) Use a dummy input load prior to adjusting dc offset, (ii) Don't use D5 on carbon tracks, (iii) Use white vinegar for removal of corrosion, (iv) Clip before soldering (I've always done the opposite).
the lesson on the potentiometer is worthy of a university lecture,well done
Tony... Very, very informative... And I genuinely appreciate your videos. Finally, I know where to begin correcting my naïve deoxit madness on my Pioneer SA-8500 Pair.
Tony, thanks for great and invaluable videos. The insight and knowledge you share is 2nd to none and something i would expect to pay for. Please keep them coming. Even though i am no Engineer I now feel able to tackle some of basic maintenance that these great works of art require.
At 13:05 you stated that there was no Digi-key, no Mouser back in the 70's. Actually, there were both - Mouser started in 1964, and Digi-key started in 1972. They put out heavy thick free catalogs, and you would either get on the phone and call in your order, or send them an order in a letter. I always just called Digi-key, they were always friendly and fun to speak with. Both have been online for a long time, with easy-to-use online catalogs and ordering.
I used to do mail-orders from Digikey (in the late 70's) when I was building Heathkits and I wanted better parts..
Great info Tony. Seeing this makes me wish I still had my SA 7800 from back in the day. Thanks for showing the actual soldering on the PCB too.
It's great to see these nice old amps being maintained and going for years!
Perfect timing. I'm getting ready to clean mine to day. Will have to wait for the products to come it. Thanks
Love those Hakko scolding irons and desoldering stations. Have them at work
It be noted that scratchy pots may also be caused / exacerbated by surrounding coupling capacitors with excessive leakage current putting DC on the wiper, so always keep this possibility in mind as well. This particularly applies to lower-voltage parts and will be a function of capacitor series and age, given that electrolyte composition has changed multiple times over the years and long-time chemical stability may vary.
That why I always yank out all those fuckers no matter how they test. If they are over 20 years old they get yanked
Oh cool that is my first amplifier that I loved so much when I was a teenager. I worked a long time to save up for it!
GREAT Video! Excellent explanation of cleaning solvents! Thank you!
Great video and some good tips. I have a Kenwood KA-7100 that I use all the time but it too has a scratchy volume control among other minor issues that will require some troubleshooting. I also do some refurbs as a hobby so have decent equipment. I'll be using some of your tips on my Kenwood especially the tips on cleaning the pots.
Great job, thanks for sharing
Thank you so much! My Dad has one of these, so we are looking into restoring it.
Discovered the hard way while repairing a Moog synthesiser that those carbon track wafers are really easy to destroy with the wrong chemicals. Luckily, CTS pots still use the same wafer design as they did in 1981, so I was able to buy some new pots (with a different shaft), swap over the wafers and lubricate them like new. Sharp side cutters are brilliant for getting under the bent tabs to get them open!
Thankyou very much sir for all the tips. Im rebuilding my old STA-6080 REALISTIC.
Thank you Tony for sharing your tips. These Deoxit sprays are not available everywhere, but there's always some decent manufacturer doing something equivalent nearby... You should also explain why these volume pots are so difficult to replace with their intermediary output designed for loudness circuitry. Most of these are nearly impossible to replace, and when you manage to find some equivalent, they generally come in expensive order made monsters. So everytime you intervene around these, it's never such simple operation!
I also remember the pre internet period, when you could find shops selling components in nearly all big cities, but they generally sold basic crap and kits, and rarely or never any Japanese transistor. Here in Europe, even big retailers avoided them because of duty taxes, and you have to know the right address in a crappy suburb to find "the Vietnamese" selling marvels in his garage... It's now far more easy to find some Chinese (fake?) components than real stuff in dedicated internet shops (Germans are particularly efficient about audio components, UK sellers are now unavailable...).
It could be very interesting to compare our typical command list!
Nice amp tony, always loved the classic silver pioneers from the late 70's
Yay, Sunday with Tony!
Thanks for going over your two-stage cleaning process and your recommendations on chemicals.
(Now of course the price will go up on all the brands you named, more's the pity)
Oh, Caig foresaw this video, they are already ridiculously expensive!
In the 1960's the Pioneer SA series were given high praise from leading audio magazines and considered one of the best sounding amps that money could buy.
this amp is more 1975 time frame
11:00 Clipping the lead off before soldering is the way we were trained when working on military circuit boards. No more than pad height on clipped length, so like a little triangle. No copper showing when looking under a binocular microscope.Probably too fussy for consumer grade equipment, granted.
instablaster.
Great tips Tony. Thanks for sharing.
Very informative video, Tony. Many thanks!
Awesome stuff 👏
I remember once having to get a replacement rectifier diode for a Dyanco 120 Power Amp in the early 70's. The house didn't have the stock part so they talked me into buying a 4-pack of these "shiny silver" power rectifier diodes for about $10.00(!). I was able to obtain a closer match diode at a local Radio Shack for under 1.00. I still have those "space age" silver power rectifiers. I use them for lab work. So at least I got my $$ worth off of that adventure.
Potenciômetro difícil de encontrar o jeito é recuperar já passei por está situação 👏👏👏👏
Hi, I always learn so much with your videos, if you allow me the observation, I think that plastic at the end of the potentiometer rotates 3 or 4 degrees in relation to the shaft and allows to correct the balance between the two chanel's when the balance potentiometer is at center and there's some mismatch in volume, I have a pioneer SA3000 integrated from 1979 and I was about to replace the potentiometer when I found this and solved the problem
I love these things. Thanks for the video.
Thanks Tony for the info on the use of fader lube. I switched over to it because it made more sense. What is a carbon track pot but a fader! Great vid as always.
Great presentation sir, thank you!
Very nice !! I am hoping to be able to determine the values of the multi turn pots so I can replace the ones in my SX-737 when I work on it soon. I am going to print the schematics.. hope they either tell me or something can be read from the originals. I think it's a great idea to upgrade those !
I grew up in Santee, CA, and getting parts was just a quick drive to the Mouser headquarters store. I was lucky.
Yeah, didn't know how spoiled I was with close components. I Lived on corner of Fanita and Prospect :D
Great tip at the end of the video!
Thanks for sharing Tony. Fred
Yes there is much misinformation about which cleaners to use. I'm using fader for pots and the 260d grease when I can take them apart. For metal to metal switches it's d100 followed by shield. Since I still live in CA I can buy syringes, over the counter, (or not shower and get them free from the state, lol) and use them when I need precision.
I've had a 7500 and a 7500 II. They both sound good, but the 7500 is sooooo much easier to work on and just plain laid out better. (Even though it's 5wpc less than the II version, I prefer the 7500.)
This is so weird... I use exactly the same amp for exactly the same purpose as you. My dad bought it for me many years ago and I've used it ever since. These retro amps seem to be becoming desirable of late. I just think it's a nice sounding amp.
Interesting circuit!
Damn, I used the D5 to clean my sa-8500 pots. It worked, so I hope I didn't ruin the carbon. Will use F5 the next time.
I think you must be about the only person in the world who has an SA-7500 for a computer amp!!! (BTW my computer amp is a NAD 3020, not quite the same vintage as your beautiful 7500 but gets the job done)
I use a fully restored kenwood ka-701 (it was a basket case when I got it and hence was a cheap purchase, knowledge is power) that replaced a refurbished ka-7100 (the 701 has a lower signal to noise and it's noticeable with digital inputs). Very quiet 1980 vintage amp. It's runs off of a claro halo sound card with rca outs and powers a pair of klipsch fortes and some fostex th900s. Great sound and it's used for digital music and web vids like this one. It also looks great on top of my computer desk. More people should do this since these are great headphone amps (better than new amp on a chip amps) just pick your poison pioneer, marantz, yamaha, kenwood, sansui etc.
I have a Sansui AU-5500 that I use for my computer amplifier into a set of small speakers and a powered sub hooked to the preamp out jack. Sounds is amazing.
It's connected to a pair of Energy Point-One-E bookshelf speakers. It sounds great with music, and is extremely clear when listening to voice. It also has a really nice headphone output that gives a noticeable improvement over the computer's headphone output. Thanks for the comment!
@@fernarias here in the UK I use an old but good Soundblaster 5.1 PCI card into a Quad 303 power amplifier, that fed into Rogers BBC LS3/6 Monitors.
I'm still using a "modified" Sony TA2000f as my main preamp / control center. It's basically the Sony version of this. It's got a noise issue in its main phono stage, but I don't use it. I use a newer external phono stage.
11:24 That Kester SN63/PB37 "44" Rosin core Dia .031 is the best for this kind of work. That is what I use.
Thanks for your education, I am learning a lot !
DC Offset. I've noticed your concern about this. I have enjoyed recording since '75.
And have noticed some equipment (mics n mixers) introduce DC offset to the
waveform. This has become very common on the net. It is very hard to remove
post prod'. An adjust for DC offset on record checkbox on software is good if
effective. Some channels on ut are severe showing clipping on the upper or
lower half of the waveform ! I have not checked your channel (yet) : )
I am not sure if it will be passed on to the amp. Should I worry ?
Glad you brought this up. This question somewhat ties in with the video I am currently working on. I will try to address it there, if I remember :)
@@xraytonyb Yes please. I look forward
to that, thanks again.
Great explanation and thanks for posting this. In my 60's and as a career electronics tech I love this stuff. One question regarding the tone board drivers; You stated the original PNP as 2SA725 and 726. You did not mention the original complementary NPN number. My NTE catalog is outdated and has no listing for replacements, KSA992 and KSC1845. It however shows the PNP replacement as NTE234 but without the original NPN number cannot cross reference. Could you provide? Thanks again.
Thanks Tony !!
That spray-in stuff manufacturer that starts with a "C" and ends with "aig" actually offers an attachment with a cut off syringe needle at the end. Overpriced, of course, but very handy!
Those new cans are terrible. I've had the had the hinged area of the yellow "fire hose" leak on me more than once, which will keep my hand from corroding, but does nothing for the switch I'm trying to spray. A lot of product is wasted. The yellow fire hose also doesn't fit in the opening of many controls because of the diameter, but of course you can buy the overpriced needle attachment ;)
I had one of these amps when I was a kid and would like to find one to buy
That deoxit stuff is mad expensive this side of the Atlantic tony
You can get similar stuff in most places.
In my opinion, it is extremely overpriced over here in the states as well. It is a good product, but I think it is a waste to use it for the cleaning process. That's why I use an inexpensive cleaner, such as that CRC product (there are many brands that all contain the same product) for the cleaning process and then just the smallest amount of expensive stuff as a protectant/lubricant. A can of the expensive product lasts a very long time, when used this way. Also, I can't stand the "new" container that caig uses with the huge yellow "fire hose" on the nozzle. If you look around, you can still buy the can with the standard nozzle that has adjustable output and can accept the standard red extension straw that comes with every other product. I see no advantage to the new container, other than wasting product and making you have to buy a new can sooner. I also think the overpriced needle adapter for the new can is not as good as the old design. Thank you for the comment!
Okay, I'm paying special attention to this one as my SA 7500 has tone control problems.
When I turn on the tone control one channel drops a lot in volume.
So where I am (Philippines) Deoxit cost $50 per can. Do anybody know of a less expensive but equivalent cleaner available? Thanks in advance.
I have to mention how incredibly valuable these videos are to me as a non-educated diyer. Thank you so much for the Pioneer videos, please make more of equally high standards and keep up the great work and channel.
I just bought an SA-706 but after seeing this video I I think I’ll sell it and find a 7500 because of this and your other documentation.
Hi xraytonyb.
Thank you for this video. Good job.
I have a question about how you have placed VR2 in the PCB. The question is: Why this VR is placed just the opposite of VR1?. Looking the scheme, it looks that both positions must be the same in order to obtain the same resistence value when screws are turned to left.
Great explanation!I have a cracking noise from my equalizer amp (I have a SA-5500ii) and I guess have to replace the 2SA725 with the KSC992FBU. Would you recommend to replace the 2SC1312 too? (perhaps with a KSC1845FTA?)
Thanks Tony, You realize of course that we are all going to run out and get the Dexoit F100! :) I have a question, why did you remove the pre jumpers and install those terminators (5.1k) to set the offset? I have never done that before.
Any ideas of cleaning off circuit boards which have been saturated with deoxit cleaner? There was a product called Electro Wash, but have not seen it in years.
Hi there . I use MG chemicals ( Safety Wash 2 ) safe on plastics
@@lloydparks4974 Thanks, that is exactly what I was looking for. $20 for 16 oz. on Amazon for the aerosol can, or $17 for the 1 liter bottle. I was thinking of using an extra waterpik dental cleaning device as a mini pressure washer. May or may not be practical, will have to try it.
Great info about Deoxit, thank you very much.
Is CRC Di-Electric Grease any good for lubricating potentiometer?
No! "Dielectric" means insulating, putting it ito a potentiometer will alter its characteristics drastically or render it useless all together. Greasing up a pot, you don't want to introduce anything that would or could change the resistance between the wiper and the resistor element.
@@ampdoc I see, thank you.
Woah, that looks increadibly similar to my amp, a Unicef Model TA-5300. The only thing is that I have the only known amp of that model, and even brand, so I'm eager to find any info on it. Do you know if Pioneer would have sold an amp like this or in this series under a different name, or sell the design to a other company? Any help at all will be massively appreciated.
I know that Pioneer marketed products under several other names, such as Centrex and sonic (maybe sonics). Most of the non-Pioneer branded gear was at least slightly different from the actual Pioneer-named products. That being said, I wouldn't be surprised if your unit was made or at least licensed by Pioneer. Thanks for the question!
Hi Tony! Thanks for this; interesting stuff, especially on snipping before soldering. One observation - when you were cleaning the flux, you applied alcohol and brushed the area, and I thought you might use a paper towel or something and absorb all that diluted flux, and then repeat the performance for even more cleaning, but it looks like you sorta left it there. My theory is that what you mostly accomplished was just diluting it and flowing it into a thin layer, rather than removing it. Does that make sense?
I usually don't wipe the flux with a paper towel because it tends to make the board sticky and the towel sticks to the flux and makes it look bad. The flux is the non-corrosive type and doesn't hurt if it's there. Many times, the boards have flux on them from the factory, but the heat from the soldering process makes it flow out smooth and shiny. If you've ever seen PC boards with a hazy white film on them, it's because that flux has gotten wet from contact cleaner or someone tried to wipe the board down with a rag soaked in alcohol. Using a brush or cotton swab soaked with anhydrous alcohol (no water content) will clean up most of the flux and let the remainder flow out into a shiny finish. You can scrub all of the flux off of the board, but it can be a lot of work, as the more you wipe it, the more it just spreads around and reconstitutes the flux around it. I guess there is no right or wrong way to do it, this is just the method i usually use. Thanks for the comment!
so for this one, you commend contact cleaner + fader, or do you think the Deoxot green spray is just as good? Was using just the lube an improvement?
Can you give any direction what I can do to to diagnose a no power situation in my SA 7500?
What is a general maintenance usually consist of, the very basic is what I am looking for
Hi Tony, where did you apply the DFG-213 onto? Apply to the same spot as the contact cleaner and Caig fader cleaner (small green bottle)? Thx.
Hey Tony, great video as always! Many people still have long term success with WD-40, what are your thoughts?
Thanks for a great video Tony. I've always wanted to know what dc offset and setting the bias was for. Is it possible to measure directly at the speaker outputs for adjusting dc offset?
yes just take away the load
Hello, I wanted to ask if there is a dcoffset, and there is a protection circuit, the relays do not click and there is no sound, what to focus on, please look for a bug, thank you for any comments
I also have 7500 and since I've had it, the stereo setting has not worked. It only plays from the right channel. I have to keep the amp in Mono to get sounds from both speakers. Any chance you can help me with this?
a stackable pot like lego would be nice. want a 100k lin coaxial with a hollow shaft, 20k log stereo, 10k lin and a switch at the back, just stack the modules as needed.
I am looking for good headphones for this amplifier. What impedance will be better 80 or 250 ohms? I would like to buy Byerdynamic dt 990 pro.
realistic/archer 2022 is a compatible replacement for 2sa725
I'm a bit confused. You said the 2sa725 was a PNP, and the 2sa726 was an NPN. The data sheets say both are PNP. Am I missing something?
They are both pnp. I misspoke. 😞 sorry
@@xraytonyb LOL That's ok. Thank you for the speedy reply!
QD5 to clean, Superlube to lube. Not sexy enough for videos but it works
Good session. Love the pot cleaning techniques. Is that white vinegar or the regular type? Thanks.
It looks like distilled white vinegar.Not the brown malt vinegar.
Mind you, the smell makes you hungry either way !
35:35 It is better to build this procedure on an analog tester (arrows). It's proven and useful, bro! After all, you have them!)
Your power supply capacitors are terrible. You need to put Nippon Chemicon, only them! Thanks for the topic and excuse my English!)
I use Acid Brushes. Cheap at Harbor Freight.
His wife's cosmetic brushes are cheaper.
@@drp457 true
good tip! Thanks!
@@xraytonyb Which tip?!
What type of transistors did you use for the 2sa726 on the power Amp board?
I'm guessing KSA992, but there may be other options like the KSA1015 and KSA733.
dlucy over at Audiokarma made a flowchart, you may want to take a look at that: www.audiokarma.org/forums/index.php?threads/transistor-substitutions.688515/page-7#post-11865547
do the transistors on that strip of cardboard have the leads in a different order?
Yes, the 725 is B-C-E. The 992 is E-C-B.
How is it you came up with Robbie the robot as your channels emblem?
(I'm sure it's been asked many times before but I've never noticed it in any of your videos) Gort
That’s NOT Robbie the Robot! It’s the robot from Lost In Space. It is a B9 class environment control robot. 😀
@@jimomertz Well spotted.
I have too
how many watts per channel do those have?
I use surgical spirit to clean old potentiometer's, is that o'kay
Surgical spirit is primarily alcohol. I don't know if it might desolve the adhesive that bonds the carbon to the wafer. If the pot still works you might just need to add something like the Fader Lube
Surgical spirit often contains other chemicals which may or may not be ok. They might leave residue.
Have you seen the silicone version of WD-40*? It probably leaves a silicone oil residue.
*"WD-40 Specialist Silicone Lubricant"
I have used it before. It works well for small mechanical parts, but I would not use it for any electrical contacts.
con pioneer sa7500 nay jong y trang con pioneer sa7800
Aren’t you supposed to lube the shaft of the pot too?
The volume shaft has a dampening grease. Once it's dissolved It is virtually impossible to replace.
Well you could get the grease in there just use some grease on a thin piece of card just work it in.
you can make your own contact cleaner 70% mineral spirits/white spirit, 30% isopropanol 99% 10% mineral oil WD-40 mix together put in a syringe with a blunt needle no spraying is needed you could substitute the isopropyl for acetone if using on metal contacts only.
Lelon caps. Those are garbage, Tony !
Oh no. Another tech pronouncing the silent "L" in "solder."
L rulez!
Спасибо, профессор!!!
Great tip at the end of the video!