How to repair Wangs Tube Guitar amp Excessive tube current strange issue
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- čas přidán 7. 07. 2024
- This amp was shipped to D-lab with a unique problem. Output tubes running hot, distorted output. A very nicely built amp, super nice eyelet board, excellent solder job, however poor quality tube sockets caused a major issue. I plan to change all sockets with Belton type, plus re-tube completely. At first I was stumped, then lucky for me, with a little poking around, the defect revealed itself. So as you can see, beware of this type ceramic tube socket. They look pretty, shiny, some have gold plated pins, however it appears that longevity is not one of their strong points. Tube amps back in the day are still running with their stock sockets. If you want your hand built amp to enjoy the same or close life span, spend a little extra upfront. I normally use clean NOS sockets, but if I need to purchase new, I go with Belden Micalex. The Tubedepot,com sells them at a very good price with quantity discounts.
- Jak na to + styl
Nice to see that gentleman's Wangs all fixed up!! Great job and video!.... :-)
This tube socket issue is rapidly becoming more apparent as these parts reach the five to ten year mark. Just had a repair myself with this hidden problem, so I can't thank you enough Terry.
I think the issue is the quality of the metal used on the pins. It just degrades over time and a black dust that looks like pencil lead starts to appear. Not only that, but you can't retention because the metal is just too soft. Cleaning is only a temporary solution.
Awesome job Terry!! You never cease to impress.
I love vintage Tube Amps. You keep our history alive!!! Thank you for sharing your wisdom with the world!!!
Great troubleshooting Terry! Very methodical, only changing one component at a time. Great tips.
Very good video. Interesting to see a wangs amp inside and being tested!
God Bless you Terry for sharing your wisdom with us!!!
Hi Terry,
This repair reminded me of watching episodes of Quincy M.E. or Columbo back in the 70's ...
Either one applies here.
Yet again you performed another fine forensic analysis to get to the root of the problem.
Glad to see you're back working on tube amps again. :-)
Outstanding job Terry. The mark of a pro is that they make it look easy. I hope you have a really nice D-Lab plate to rivet to the chassis!!
Hi Terry, I've been waiting for you to get back into guitar amps. Thanks for sharing. Great job!!! Happy New Year!
I like the way you tracked down the problem with this amp.
P.S. That guy can package our equipment anytime.
I really appreciate this video Terry. I built a pretty complex amp for my first build and after about 5 years I had the high current issue pop up. That was about 5 years ago, and it has set in my closet since. This may be my problem! I will check it out. Thanks again.
Nice job Terry
Great repair sir, you make it look easy. This is super channel. Salute!
Great video Terry.
A modern take on point-to-point wiring, ruined by poor part selection.
Very interesting video... great watch.
Well done sir. 👍
D Lad in da house with a new guitar amp video. Whoop Whoop!
You are an artist! Fantastic!
What an great insightful video.
Old Battle Creek Michigan! I was in the Air Force as well and I was once deployed where a group of A10 Guard guys from Battle Creek. They were a great group of guys.
Wang is a Chinese-owned company. I'm sure they would like to hear from you regarding the subpar tube socket components. I ran across a video of a factory tour of Wang on CZcams. They seem to be very interested in providing quality products. I'm sure a brief check of the internet will produce an email address. Thanks for the informative video.
This is my favorite show on the web.
That looks like 50 watt Marshall clone. Excellent wiring from the factory. I was surprised when you turned it over and saw a turret board. It also looks like they copied Bruce Egnater’s cosmetics. Another good video with trouble shooting. Thank you Terry.
It is an updated clone of a Plexi. Wangs manufactures this amp (1987HW), along with a 2204 clone and a 30 watt Bandmaster clone.
Finally some more amps!!! Just messing with ya. Keep em coming.
Awesome, as usual.
Nice work fella
Tube socket rock-it! For sure.
Great diagnostics Terry. Love your videos! Those cheap tube sockets and cheap switching jacks on FX loops are the downfall of many a good amp. Seems like once a week I come across a dead amp with a bad switching jack. One of the first things I check lately if nothing crazy is going on voltage wise.
Great point on those FX jacks. Yes, I see many failures causing preamp drop out and static. I never install effects loops in my Homebrew amps for that reason.
Just did a SS Ampeg bass amp that switched out the speaker to use with heaphones via one of these jacks. Contact was all charred from arcing out passing that much RMS via that tiny contact when using the speaker. I imagine it had never been used with headphones. Was a good quality Cliff jack too. Bad design all around on that.
Awesome!!!
Awesome video! even a total amateur can learn how to troubleshoot tubes from this. and a consumer can know what to expect. Judging from this video I would say it's a great amp and it's super repairman friendly but you can guarantee it's going to need repairs LOL but hey once you get a good tech to swap out any sub-par components you've got something (depending on how the transformers hold up) as good as a real 70s marshall and still come out ahead a ton of money!
YAYYY, D-LAB!
Nice troubleshooting, Terry. Thanks. Did you run out of wine?
Good man!
I was suspicious about those sockets, too. Another great video. Thanks, Terry.
Nice!!
Terry, you should show us a little more of the actual soldering job
Good one! Who expects poor quality parts? Seems to be a trend these days :-) True that on using quality parts!
Terry, your address is open for all the kooks to see. Your a great bloke hate to see weirdos knocking.
Keep up the vids
Wang computers subsidiary? I have an old Wang monitor, offset yoke.. weird thingy, wish I had the desktop it probably had with it.
It's interesting that they used sockets mounted to the chassis instead of having a PC board with the sockets mounted to it which is a quality move BUT then they cut a corner and used cheap sockets that were prone to failure.
Frank Zappa said, "Cheapness has nothing to do with the budget of a film. But, it helps!" Same goes for electronic components.
Good job Terry. Those sockets look like someone sprayed something in there and it had a reaction to the metal. Either way,. those cheap Chinese sockets are not made well and for sure need to be ripped out of there. Do you have a usual supplier of sockets ? I always struggle finding good ones after being burned on Amazon a few times. Great job as always my friend - Ron
Jeepers, and I thought I only got the weird cases. I have a '65-ish Princeton (non-reverb) on the bench right now with low voltage (126v) on Pin 1 V2 when it should be 260v...Need to go point-to-point in the trem circuit and find the offender. Problem is not the tube.
So terry what would be the proper way to switch from pentode to triode mode ? Schematic would be helpful. Tnx
This is why I like to tear down old tube test equipment- for the sockets. And if I need an extra one there's a shop which will sell me Cinch-type ones for around $4 apiece.
Ol Mama San didnt charge Mr Wang no extra for that quality build lol
I was surprised to see the point to point simplicity of that amp when you first opened it. As a Chinese amp I expected some printed circuit modules here and there. I see where they get you is in those tube sockets. Great video, Terry. I've been enjoying your Ham Radio stuff as well as I grew up around it and have kept an eye on it through the years.
Outstanding video, Terry!
Where are you located in the lowed 48?
And are you still taking in valve amp work?
Thanks for keepin our era alive!!!
They're a well known Chinese amp. Pronounced Wong. Mostly built quite well, apart from the usual Chinese parts that may inevitably let it down.
Using crap sockets is just Wong.
@@electrofrying1685 Sadly, that's the truth for a lot of affordable amps.
I've been getting many amplifiers in for repair with bad tube sockets. The sockets that are made in china, are of poor design and are cheaply made. I also use Belton Micalex as replacements and never had a problem with them.
@@electrofrying1685 Probably poor material selection on the socket, instead of a high quality plating they went with a cheap nickel plate over a steel pressing, and this works for a while, till the porous plate degrades from heat and corrodes.
Great video! I recently got a used Wangs 2204 clone really cheap, so cheap I couldn't pass. It's not PTP though, it's PCB, and it sounds good, no apparent problems, but I feel like the power tubes are heating a little too too much. I opened it up, but it doesn't seem to have a bias pot inside. How did you bias that one from the video? Changing resistors? Also, what do I need to check the bias on mine? I saw on this video you were checking pin 5 and pin 1 perhaps? Can you confirm which one I should use to check the bias on mine? It currently has a pair of JJ's E34L in it. Cheers from Brazil!
Wangs is an American amp company who builds their amps in China. They make handwired clones of vintage amps and they sound amazing. However, they use cheap, Chinese made parts so the build quality and reliability suffer greatly (as demonstrated in this video).
Can a tube socket be used with brass contacts and solder terminals in hardened porcelain bases?
Check out the Back of the "Wang"
I love Chinese Wangs
Just say NO to Chinese tube sockets! Good job Terry.
If you remove the second tube you effectively disconnect the first one from the rest of the circuit. The problem is still there in the first tube, it's just not making into the power stage
I tried it with just the 2nd tube installed, 1st tube removed. Watch the sequence again. The tubes are OK, sockets not
@@d-labelectronics
At 7:50 you test with none of the preamp tubes installed, no issue.
At 9:00 you removed the second tube, and put the first one back in, no issue.
My point is that the second test was redundant. If the issue was not there with none of the preamp tubes installed, it's clear it won't be there with only the first tube installed, even if the first tube is actually causing the problem, because pulling the second tube out breaks the signal path between the first tube and the meter.
Note, whenever I say 1st or 2nd tube I mean whatever tube happens to be in the 1st or 2nd socket, not any particular 12AX7
A lot of racist crap going on in these comments. Poor quality components are not only found in Chinese equipment. I have Fender Super 60, notorious for having lousy input jack sockets, and, yes, mine failed within a couple of years. A fine bit of detective work, sir.
WANGS amps (pronounced WONGS) is a privately owned, family run company striving to build high quality amps. A truly independent Chinese business trying to make it on their own. BOUTIQUE, Americans might call them. They advertise ceramic tube sockets as if it's "boutique" feature; this is quite interesting to see as I've been curious about these.
Wonder if anyone from Wangs amps has seen this video & addressed cost effective sockets?
Yes. Better QC
@@wangsampshello Wang's amp, I'm just wondering why you chose 10 ohm current shunt resistors? Can they be easily exchanged for 1 ohm? Will that affect the amp in any adverse way? Thank you
@@wangsampswas it your intention to read the voltage across the 10 Ohm resistor and shift the decimal place to determine the milliamps bias?
Hi do you know what the fuse value is in a Wangs mini 5? Mine keeps on blowing them. Maybe needs a more resistant fuse?
Bingo bango.... :-)
Put a good resistor on it.
It might have gotten wet or been in high humidity at some point and the crap chinese metal in the sockets oxidized.
I’ve seen these, they are manufactured by Biyang/Joyo this amp is a clone of a JCM 800 2204
A counterfeit copy, just goes to show ya... they also make Ching-a-ling copy cat cars, such as a Toyata look alike, but a hunk o' junk. This is why Chineeeze sleeze cars are not sold in the USA, can't pass the standards. Volvo is now made by Geely, scarey!
It's a four-input, non-master-volume amp with "Normal" and "High Treble" channels and "1987HW" printed on the faceplate. That's a JMP50 1987 50W plexi, not a 2204.
Matthew Whitworth Yep you’re totally right, I didn’t even notice the 4 input, I just saw the 2 el34’s and assumed it was the 2204 clone...Cheers!
jobyregrets
Biyang and JOYO are not affiliated with each other
Terry, aside from the sockets, did these amps seem well built? Those cheaper sockets are what you will find in most lower priced tube amps anyway. Even though ideally they'd already be better sockets; if the rest is done well, a small extra investment in better sockets to have a solid hand wired tube amp doesn't seem that bad.
Yes, besides the cheap sockets, I was impressed with its construction. Have no idea how long the transformers will hold up. The metals/wiring/insulation could be an issue in the future.
D-lab Electronics thanks for the input. I bought one of their less expensive amps a while back and it’s held up well so far. Most amps in that price range seem to be hit or miss with regard to transformers. If the tube sockets are the only definite concern, I’m taking the gamble on a hand wired model. I’ve followed the brand for a while and haven’t seen any issues mentioned with transformers failing. It seems very common with the western brands who outsource their lower end amps to China.
Hi. Tuob el34.. Chena.. And phlpis 😵
What do they make as a jcm 900 clone before I have to go buy a peavey windsor
Hadley Scott McIntyre
No 900 clones just two “Handwired” clones right now.
#1987HW (‘59 Plexi)
#2204HW (‘74 JMP/JCM)
Wouldn't an inverter turn DC into AC while a rectifier does the opposite?
Got a o'scope ??
The transformers with Chinese writing on them would have me somewhat concerned about longevity
Not really, transformer manufacture for the steel core type has pretty much been gotten to be very reliable, and they are using a decent amount of insulation in them. CCA wire more likely than not, so you might have connection issues long term as the soldered ends degrade, but so long as it has been properly vacuum impregnated with varnish there should be no issues with the solder joints.
It's the metal. Chinese use recycled metal for everything. it's the same mix for wire' , tube sockets,pot cases
Yes, those sockets do not look good.
Great trouble shooting those great china parts.
So the plate voltage is low?
Hello, I have not directly measured the plate voltage yet. I will make a follow up video showing the completed repair, give it an ON the air test, measure output tube voltages + bias settings. I am adding Master volume to this amp.
@@d-labelectronics hey thanks! I love tubes and I love learning about the amps.
I just thought since the current was high it had lowered voltage.
I assume everyone saw what actually happened here.
hmmm, China... it "WANG" the WONG number!
China, never stops giving 😤😬
50 dollar box for a 25 dollar amp
I have worked on a wangs before and that doesn’t look stock. Almost like someone has put a ceriatone kit jtm board or something in there .
I have no idea, this is the first I have worked on.
ShepsGuitar What does not look stock?
You probably worked on a PCB model..Wangs has 20+ models from 1w to 100watts both HW and PCB.
This is not a Kit from Ceriatone but handworked at Wangs Custom Shop in North Shanxi.
@@wangsamps Great amp Wangs!! It should get way more attention because it's amazing. Did you guys address this issue with the tube sockets? By the way I just ordered one today can't wait for it to arrive.
Do not believe resistance value
Wang, is pronounced wong, so we’re all straight!
Buy UsA
Ahhh chinese QA...
"China, never stops giving" ... Ain't that the truth!
Pronounced Wongs lol
Chinesium tube sockets suck
You get what you pay for, steer clear of Chinese made guitar amps.
Thanks for this video. You just talked me out of buying one of these commie amps. Was prob made with slave labor anyway.
You're right you should buy the SV20H instead. The marshall is 3 times the price and doesnt sound as good. The wangs has amazing tone and percussive bass that you feel in your chest. Apart from these tube sockets every other component is literally highest quality. Not to mention point-to-point hand-wired. Where else are you going to get that for 900 US dollars😮