The Amp Garage

Holy mackerel, look at the shafts on those pots!

Tube rectifiers have a limit on how big that first cap can be - not so with solid state rect's - you can go into the hundreds of UF if you really want to (not a bad idea in a bass amp) but I do like to lay a few diodes in series if that's the case, just to increase the current handling spec of the r...

Voila my custom pine combo cab from Mather, finished in tung oil. I nearly fainted when I saw it for the first time, they do amazing work! Pretty scratchable though, definitely more suitable for studio than van/roadie abuse.

I have to post a dissenting view that the glass gt's feel much more responsive and 'alive' than the metal can tubes - I've found this to be the case with other can type tubes, don't know if the metal adds capacitance or what, but they have a dull feel to me as a player - but can in a sense sound smo...

Sounds like a mechanical vibration - you can completely isolate the amp from the speaker to test (if noise goes away, then yes, it is mechanical).

If that's the case, I'd first just try a new set of tubes. If that doens't help, I'd do some chopstickin'...

St Peteresburg?

You might find this link interesting: http://aga.rru.com/Events/MM-DRRI-rebuild/

I have done a hell of a lot of research so far, but I am in danger of drowning in a sea of data and internet "opinion fragments" lol If there's one thing I've learned in all my years of reading forums, it's not to trust internet opinion. :) Having said that, if you go for the Sozo blues, please pos...

Check out Allen Amps for some very affordable and well made Heyboer Fendery transformers! No need to go broke on Mercury, imo...

...plus, if this is an AC15-alike, or other cathode-biased design, you don't need those .1 uf caps after the MV. In fact, you don't need them even in a fixed bias amp if you just connect the "bottom" lugs of the pots to the bias supply instead of to ground - as the bias supply should already be at A...

Test that sucker for DC leakage if you're putting it in an amp....

I've got a ceramic blue dog and it's usually too smooth to my ears in most places - might actually be what you're looking for! But if you're currently using new speakers, be sure to let them break in for 40 - 80 hours before judging the amp too 'harshly.' NFB is a strange thing. Depending on the pow...

Honestly, that seems like a fine load for EL34's to me, not knowing the plate or screen voltages at least. I always found the mythical 3K3 primary Z on EL34 Marshalls to be almost unacceptably high, at least when the screens are at or near 100% of plate voltages.

+1 on everything. You can use both PT legs and full-wave rectify the bias supply if you want to, but you are solving a problem that is not there and using extra parts, and you know what they say: "mo' parts, mo' problems." I always get the maths wrong when a half-wave rectifier meets a resistive div...

You might be able to find an operating point where they are both happy at the same load. Adjusting screen voltage will go a long way towards this. But most likely, nothing will blow up if you just pick a point halfway between the two.