The Amp Garage

The major does not feel much louder than a superlead necessarily but it has a different feel and tone. It offers more power and punch that affects bass and mids a bit Makes sense in terms of the 3db difference as power doubles. I haven't looked through too many Major gut shots, but at least on the ...

To me a "JTM45" with EL34s and a 3.4k OT is not a JTM45. When Marshall changed to EL34s with a different OT, the amp was renamed JTM50 and later JMP50. So if you want a JTM45 sound, use KT66s with a 7k to 8k OT. EL34s will give more power (around 50W) while the original amp with KT66s and 8k OT onl...

along with the very high voltages in the Major, make it much cleaner than other period Marshalls. It will also break up differently and respond to pick attack differently. The major does not feel much louder than a superlead necessarily but it has a different feel and tone. It offers more power and...

marshall major has the same preamp section as the garden-variety early 1970s Plexis, but the following critical components that distinguish it from other plexis of that era (let me know if I'm missing anything): 1) Ultralinear power amp section 2) KT88s 3) No cathode follower 4) Tone stack inside n...

I like a noload pot to keep the vox cut control out of circuit since it loads the phase inverter slightly (you can hear the difference). I mostly keep it disconneced but sometimes it is good to have if the setup sounds overly bright in one application (e.g., telecaster at low volume). It is better ...

I originally put in a Vox style Cut Control on my Marshall 18 Watt style build. Very different amp to yours but I also found it to be pretty useless. Not much later it was ripped out and the front panel hole used for a VVR pot. I like a noload pot to keep the vox cut control out of circuit since it...

different values should work. but smaller caps are faster to charge than the bigger ones. Thus smaller caps are safer to use

I replied in the thread over at gear page. Sounds like you're missing a grid leak somewhere in the preamp or a stage is being driven too hard. 56K grid stoppers on the output are massive! Usually people go lower to 1.5K. Theey were 5.6K so having 56K is not the issue. From the Aiken site "Depending...

A lil birdie told me: Super bass spec Treble channel 560p 270k v2 grid .68uf cathode bypass v2 150p treble bleeders on each plate of PI (with 47p snubber) 220k bias with 6550s 560p 270k v2 grid could be standard values for the channel mixer? Or is there a big grid resistor in addition with a bypass...

sometimes you can easily hear the arching inside the OT and the lack of power at the secondary is also a sign

how many db gain boost does it offer? 36 like an ecc83?

I've already tested this by simply bypassing one of the resistors with alligator clips. The difference is mostly in feel. But there is a subtle tonal difference as well. Yes, amp gets slightly brighter, sharper attack, faster low-end response. The difference is big enough that having it on a switch...

R.G. wrote: ↑Tue May 27, 2025 1:43 pm Hmmm. Sine wave input, spectrum analyzer or distortion analyzer.

ok for sound, but not so much for dynamic response and feel?

martin manning wrote: ↑Tue May 27, 2025 1:17 pm I think those are likely to be perceptions that stem from the increase in headroom.

not just a perception but rather results of an objective increase in headroom?

...higher voltages gives a faster response and drives the power amp harder. also it adds treble (and possibly bass) and clean headroom, giving less mids and compression I'll give you the increase in headroom, but I don't see raising preamp voltage as having any significant effect on frequency respo...