Inside the Friedman Plex (pls read description for add. infos)
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- čas přidán 15. 06. 2024
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Dual MV pot reads ca. 250k. Wired as (dual) "variable R".
NFB-R is 47k @ 16 Ohms.
Volts reading in the table during vid for the „high“ setting.
In the "low" setting, voltages in the preamp too drop by roughly 10%. B+ drops from 460V to 420V. Also the bias changes (that's why there are two bias pots) depending on running it in high or low Volts mode. - Hudba
Thanks for doing this, I had my reservations about the board mounted PTs but you have provided me with some comforting reassurance and validated my thoughts that the benefit of layout and mitigation of reactive interference may very well outweigh the benefits of chassis mounted PTs.
Very clean looking inside!
Great Vid Olaf....Very informative
PC boards are the way to go if it's well laid out, components are high quality, and issues such as vibration and heat buildup are properly addressed. The most reliable electronics EVER MADE are built on PC boards with those issues having been properly addressed.
Thanks for the comments and chance to see inside. Dave has done it again. Preamp voltages and PI are spot on for a great sounding Marshall plexi.
Great overview. Thanks.
They want almost $3k for THAT? Such a cleanly laid out basically single circuit design with all the room to work in and only minimal wiring to do by hand???
Hey Olaf. Du weißt ja, dass ich nichts von dem verstehe was Du da beschreibst. Aber ich freue mich wie bolle, dass das Video so gut ankommt. Saludos ✌🏻
Danke Dir Carsten
Great review. As i understand there is nothing special with the Plex PPIMV?
I have one i paired it with a Friedman 2x12 with Creamback G12M-65's and it sounds amazing.
I dont know excatly what you're talking about, but it looks clean and im sure the amp kicks butt. Cool review 😊
Does Friedman use the pot as a variable resistor and the viper as input and the outer terminals as the bias resistor is placed?
very cool ...thanks !
Looks remarkably like the insides of my old Epiphone Blues Custom 30 inside.
I wish someone would do a Suhr sl67mk2 vs Friedman Plex comparison.
Same here.
@@aliassaid6398 Much different build. czcams.com/video/ZIY_m_a6u58/video.htmlsi=82QAv5Ezn6zW1QuZ
@@aliassaid6398 I will not buy another PPIMV Marshall. But what I could do is to convert my 76 JMP into something like this (without the lower B+ obviously) and post the result 😀
What makes this PPIMV different than the Ken Fisher type 1 everyone uses? Thanks.
I think a legitimate concern is that we now pay handwired prices for PCB amps. May still be high quality and reliable, but the savings of going PCB aren’t being passed on to consumers.
Legitimate concern - LMAO! High quality specs, right components, upgraded layout with no unnecessary cables, etc., etc... Does anyone force you to buy it? Are you one of those Zoomers, who never owned a real amp yet keeps complaining about each and every one of them? Just .... and play your guitar, man (a good advice from some Frank)
also the amount that is saved is passed on.. The only thing that is saved is about 100.00 in labor.. this amp hand wired in these times would be 2900 to 3000... and it would be inferior..
Start an amp company. Create your own custom layouts, get the boards sourced and made, get the transformers, sort through endless amounts of tubes, populate the boards, get the chassis made, get the enclosures made, assemble all the components, test them all, ship them all, deal with vendors price increases, returns and repairs. Oh, and make 15 different amps, a bunch of different pedals, pay all the employees and make enough profit to make it all worth it.
What brand of transformer does Friedman use? What brand are those yellow capacitors? Thanks.
Heyboer xformers and Synergy Royal Mustard caps
Tolles Video, ich hab viel Gutes über diesen speziellen Master Volume im Friedman Plex gehört. Er soll zudem elektrotechnisch erstaunlich simpel sein… Kannst Du was hierzu was sagen?
Danke. Ist ein PPIMV (post phase inverter master volume). 1 Stereo Poti und 2 2M2 Widerstände (ersetzen die 220k Bias Widerstände). Ist seit etwa 20 Jahren eine Art Standard-Modifikation für Non Master Marshalls (und andere) und von jedem Tech in 30 Minuten eingebaut. Google mal PPIMV oder LarMar PPIMV.
So it's pretty much an SV20 with a neater board, PPIMV built in, and a fixed bias output section instead of cathode bias? Seems pretty dope. Definitely don't agree with the pricing, but ey, what can ya do. It's not like he's mass-producing and mass-selling them like crazy. Gotta bring money to the table.
Good summary. The switchable bright caps, linked input and mostly full power/standard 50s B+ and transformers also should be counted in.
Liked the SV20 I had, cut the bright cap off in the treble and got pleasing crunchy results.
This has for sure more ooommmppph.
@@duese888 Yes, I completely overlooked those!
That cathode bypass cap on v2 likely provides the oomph! I'm still messing with the SV20, and that's next on the chopping block. I didn't cut my bright cap, rather added more to choose from :P
how is the noise floor? little hum or completely clean?
No complaints. Very quiet amp.
I've heard the ppimv is unique. Did you notice anything about it ??
Been a while that I did one myself, this looks pretty „standard“ to me. Replacing the two 220k with a dual pot. Since I didn‘t blueprint the PCB it could be that I have missed sth. I will have a look again and post that into the description in case I can see a uniqueness.
@@duese888I would be very interested in the exact implementation of the master volume, too 😊
@@romanhausner456Dual 250k pot, fed from bias, each side to Pin 5 of each PT incl 2 x 2M2 Rs in parallel. 2M2 on PCB, close to sockets, no grid Rs. Pretty much a LarMar w/out screen Rs - as far as I can see from top of the board.
@@duese888 thank you!
The pot is wired like a variable (dual) resistor and not like a (dual) divider
How is the MVC wired? Dave claims it's not a regular PPMV. I ran a few tests over here based on his description and I believe he flipped the connections to pins 2 and 3 on the pots, added an extra pair of coupling caps and used 2.2M bias/grid resistors in place of the standard 220k. Is my assumption correct?
I can recheck the wiring of the pot in 2 days. Add caps I didn‘t notice. Output side of PI CCs are 100nF if I recall correctly. No grid Rs yes. Two 2M2 yes ( as in LarMar). Will let you know.
@@duese888 Greatly appreciate it man, thanks.
@@Octopus502 Pot is wired like a variable resistor instead of a divider, which changes mostly the taper.
I think the new master volume in the Plex is Pre phase inverter, not post.
Nope
@@duese888 Dave must be wrong then as it was him who said it.
@@WarriorOfGhengisKhan Have a look at the Friedman website please. It clearly indicates what is used here.
ac or dc heater for v1 and v2?
DC, 12 V
All "modern amps" has all the filter caps inside the chassis. Who decided that this was a good idea??? There was a reason for mounting large electrolytic cans outside the chassis or in a "doghouse". They lasted for a long time, but now needs to be changed more often. Another thing they do is placing the caps close to tube sockets and heat sinks. It's designed to break.
Im wierd!!!!! And a tech, a wierd tech.
No Close Up? You didn't talk about the 90vt variac switch.
Large amp builders just put in adequate tubes as they buy thousands
sourcing NOS tubes is up the eventual owner, like Me 8>)
The single most common service call driver from customers is tube failure. At Friedman production levels reliable tubes are a must.
There‘s the lower B+ setting (460 to 420 drop), dropping it to 90% of the „high“ setting, yes. I didn‘t read the preamp volts in that setting though.
To your first point, why are people still caring about PCB or PTP at this point? Guitarists are just… weird.
If you have a look at „Psionic“ channel, you will find some examples, where the conversion into PCB went really into the wrong direction.
I enjoy Carr, tophat etc amps. It has nothing to do with improving the functionality of the amps, I just enjoy the craftsman ship. It's functional art.
Theres no real benefit to p2p and it costs more to make and more to repair due to the time involved.
I think PCB gets a bad reputation because whilst it can be well executed and functionally optimal, it's also the go-to method of cost cutting and inherently creates a single point of uneconomical repair in budget amps. If a PCB dies in a katana, it's cheaper to replace the whole amp.
A lot of things can (and do) go wrong with a pcb, like underspecced filament traces, bad servicability or inadequate heat dissipation from the power tubes. Even large brands keep making those mistakes.
Ptp is easier to mod/service than pcb. Most guitarists who have these 'classic' circuit amps (1959,1987,2203,2204) are already at least middle aged, so to use an analogy, when your building or buying a house in your '20's you like the the split level designs, but as you get older you just don't go up those stairs as much...........working on a pcb requires more hand/eye coordination than a ptp for sure.
You have done a wonderful job explaining the advantages of a well laid out PCB construction. There are pros and cons to both PCB and PTP construction. My biggest concern with this particular build is the daughter boards for the controls and jacks. If one pot or jack were to fail, you may be required to replace the whole board for that section. That’s not a problem in the near future, but if Dave retires in 10 years and new ownership decides to not keep such parts on hand, this makes what could’ve been a simple repair much more difficult. I wish he had used traditional pots and jacks for this reason, but I understand the advantage of the approach taken from a manufacturing perspective. This exchange in ease of manufacturing comes at the cost of ease of repairability.
At least do point to point tube sockets.