For all practical purposes, Nik already offers it, or at least the platform.

The Sovtek Mig 50 is nothing more than a modded Tweed Bassman.

Take Nik's 5F6a chassis and...

1.) Replace the 5AR4 tube rectifier with a SS rectifier plug.
2.) Replace V1 with a 12AX7
3.) Increase the big filter caps from 20uF to 47uF
4.) Change the Middle pot to 50K *wrong* and double the cap that connects to its wiper to .04uF *wrong*
5.) *wrong* V1A (channel 1) change the cathode resistor changes to 1K, cathode bypass  cap changes to 220uF *wrong*
Correction:  The BRIGHT channel gets a 2.7K ohm cathode resistor and /68uF (25volt) cathode bypass cap
6.) correction: The BRIGHT channel gets a 450pF cap in parallel with the resistor between the Volume pot and gird to V2

So, whats that?...11 parts?...11 parts, 4 of them filter caps, separate the 5F6A and Mig 50.  And only two parts, the cathode resistor and cap on V1A need to be added, the Bassman used a shared resistor and cap for both halves of V1.

I think Tony Bruno's amps are incredibly well built and sound great, but he isn't the most original guy when it comes to amp design, he likes the classics, and he designed the Mig 50 for New Sensor.  He did not however design the inferior, high-gain Mig-50H/Mig-50 Midget (same amp, different chassis size).

One caveat, though I fail to see anything "insane" about 470VDC on the plates, and Nik's 340-0-340 transformer should be spot on with a SS rectifier, the voltage readings in Nik's voltage chart would imply it would actually be closer to 445VDC, he's only showing 326VAC to the 5AR4 in his 5F6a voltage chart, not 340VDC).

Darn iPhone I wasn't done yet as I was saying, do you reckon that if I modded the bassman as you describe (thanks for that, by the way), and swapped in sovtek spec trannies it would get me close?

First of all, thanks for all the info, Wyatt, this community is awesome!

The last time i changed tubes here at home, I got 562 v on the plates, and set for 70% dissipation so i biased for 37 ma.

That being said, doing a little research and testing revealed that variation in plate voltages was a result of both poor QC AND a change in wall voltages over the years. The amp's PT was originally designed to run on 110 VAC in the US, nowadays, of course, wall voltage is around 120-125 VAC. I took the amp down to my uncles' shrimp trawler (yup he's a shrimper and i used to be to) and did some testing since, due to generating our own shipboard power, i can control the voltage and cycles. Thru a power conditioner at 120 VAC i got around 560v on the plates, at 115 VAC I got around 500 v on the plates, and a 110 VAC i got around 475 on the plates. After some reading around i discovered that amp techs were getting 7 volts on the filaments at 120 VAC as well, which can't be good for tube life. That being said, yes i agree, that Nik selling a design like that would not be a great idea

After that little bit of testing, i carried the amp down to my local music store where i bought it from back in the late 90's and a/b's it with a tweed bassman and found that there was really not that much difference between them. The main difference between them was that the Sovtek was louder,  tighter and snappier, presumably due to the high plate voltages, but tone wise they were pretty close.

I think my love for the amp is more of a nostalgia thing, kinda like how one would feel like an old girlfriend and i know there are quite a few guys like me that feel the same, and would jump at the chance to have a handwired version of a Sovtek, but in the end, it seems like that it's probably better to move on.

Again, thanks Wyatt!

Hi

Seriously? I thought these are cheap on the used market?

if so, then no point in cloning, honestly.

We used to be able to get these for like a 100 bucks here. I dont know if they cost more these days, will check ebay..

Thanks!

nik

I haven't priced one in forever, but the QC was horrible.  Most modern buyers go out of their way to remain obvious to the issues, they just think it looks cool, remember it from high school, and love the idea of an affordable tube head.

Sovtek had to replace all the output iron in the original production because it was too small and most blew.  Then there were just continuous inconsistent issues, many of the dealers I know sold the exact same faulty amp over and over again just to have it returned...over and over again.

The Mig 60, Mig-50H/Midget, or Mig -100H were even worse, those were more complicated amps with even cheaper parts, more PCB-mounted parts, etc.

I guess so! I think I remember some weird caps from these, they used Russian old parts I think. Some are good, some are not.

Forgot all about this. Here is a lil layout out i made showing the mods, for informational purposes

Gregg