Desirable Transformer Distortion ?

[petemoore]

Smoothing PT ripple should have been the title...The cut/chase: will moving the plate supply down 1 'stage' of filtering in the Power supply of my 5e3 be something I might like ?
I would like to smooth the power supply, perhaps adding a filtercap/resistor stage before the filtercap/resistor that is now the B+ node.
Anyone with librarian tendancies like me know where I could take a look at a schematic where this has been done, or whether I should put a load resistor [to ground] after the 1rst filtercap ?
Having just replaced a 125E with a 2x size Fisher OT, 5e3 amp w/6v6GT's..
I notice what seems is the PT now the 'constring' for lack of better term.
It sounds like a PT constriction when the power goes up [strumming etc.] there's a noticable distortion which just sounds like power supply 'uummphhing'.
Although the general bandwidth and volume increases are favorable, it also seems to pull on the power supply a bit harder as well as give better focus to it's contribution to overall PT/PS distortion [that's the theory I'd like to test.

[pdf64]

I'm not too sure of what the symptoms you have described are, but under the conditions of 'no-signal' and 'full power', measure
1/ the voltage across the B+ transformer winding
2/ the B+ at the 5y3 output.
3/ the screen supply node

See the 5E7 bandmaster, which has an extra filter stage 'up stream' of the OT.
http://www.schematicheaven.com/fende..._5e7_schem.pdf

However, the cost/benefit of having a heavy duty choke seems to have resulted in that feature being dropped when the bandmaster design was revised.

[petemoore]

ah..you mentioned 'choke', another consideration.
''5e3'', it could be argued isn't exactly what I have here, a stage of triode now feeds a preamp output, the OT is 'hifi' [whether either iron was close to what a Tweed had could be a question I'd ask, regardless of response for now the FISHER xformer gets the job, the PT is Hammond as was the OT.
I think there is room for improvement as far as PS smoothness with this amp, I'd like to consider and weigh the various options:
1 simple: choke, and[or] 'upstream' capacitor [I'll check out the bandmaster]
2 Replace the PT...an option which I'll probably put off for a while.
Thank you for posting about the Bandmaster for me !
I'll probably take it easy and do figureing, may ask another question after mulling it over some more. Thanks again !

[ThermionicScott]

Kind of late joining in here, but the 5E7 doesn't have an "extra" stage of filtering (at least where we're looking), it just moves the plate supply downstream by one node, compared to prior and later Fender amps.

- Scott

[Bruce / Mission Amps]

Kind of late joining in here, but the 5E7 doesn't have an "extra" stage of filtering (at least where we're looking), it just moves the plate supply downstream by one node, compared to prior and later Fender amps.

- Scott

Right... it has four nodes and the first one is just part of a classic "brute force PI filter" using a choke that is big enough to handle the entire current load of the power tubes and the preamp tubes.