[sdiy] B+ Current consumption

[JH.]

UA 175 is what I've built.
Not recommended for a cheap distortion box - I just noticed that
the small signal triodes in PP sound good, in that context.

JH.

----- Original Message ----- 
From: "David Moylan" <dave at westphila.net>
To: "Michael Ruberto" <frankentron at hotmail.com>
Cc: <jhaible at debitel.net>; <synth-diy at dropmix.xs4all.nl>
Sent: Friday, January 19, 2007 4:22 PM
Subject: Re: [sdiy] B+ Current consumption


Check out the Altec 436C schematic for the simple version using a 6bc8
as variable mu.  For more complex versions check out the Universal Audio
175, 176, 177.  Schematics at this link

http://www.one-electron.com/FC_ProAudio.html


Michael Ruberto wrote:
>
> I just re-read your message and realized I missed the whole "use a
> triode" part. It's been a long day. Diode biasing isn't needed in
> something that doesn't have the .7V dead zone...
>
> This might sound wacky but since I am dealing with such small levels
> could I get away with small telecom audio transformers?
> Not sure what the frequency range is on them though...
>
> I have enough tubes to try the push/pull topology but I'll still need to
> keep it really simple if possible. Can you point out some references to
> the V-Mu compressor? Sounds interesting.
>
> M. A. Ruberto
>
>> From: "JH." <jhaible at debitel.net>
>> To: "Michael Ruberto" <frankentron at hotmail.com>,
>> <synth-diy at dropmix.xs4all.nl>
>> Subject: Re: [sdiy] B+ Current consumption
>> Date: Fri, 19 Jan 2007 01:15:55 +0100
>>
>> I don't know.
>> What I've tried was something very expensive:
>> UTC A-10 into 6BC8 into UTC A-19.
>> It's the VCA part of a Variable Mu compressor, and I just found that it
>> sounds increadibly good with overdrive.
>> I'm quite sure it will also do the trick with cheaper tansformers, and
>> other
>> triodes.
>>
>> JH.
>>
>>
>>
>> ----- Original Message -----
>> From: "Michael Ruberto" <frankentron at hotmail.com>
>> To: <jhaible at debitel.net>; <synth-diy at dropmix.xs4all.nl>
>> Sent: Friday, January 19, 2007 12:00 AM
>> Subject: Re: [sdiy] B+ Current consumption
>>
>>
>>
>> Alright so lets assume a diode biased push/pull topology. Would it be
>> to my
>> advantage to play with the value of RB1 to get an acceptable distortion
>> level?
>> Or should I not use the biasing diodes? ;)
>>
>> I've never built anything with audio transformers before so I don't know
>> what parts to consider. Any suggestions here? The power amp accepts an
>> input
>> up to 600mV.
>>
>> M. A. Ruberto
>>
>> >From: "JH." <jhaible at debitel.net>
>> >To: "Michael Ruberto" <frankentron at hotmail.com>,
>> ><synth-diy at dropmix.xs4all.nl>
>> >Subject: Re: [sdiy] B+ Current consumption
>> >Date: Wed, 17 Jan 2007 19:39:15 +0100
>> >
>> >
>> >
>> > >If I wanted a clean sound I would just patch my Presonus TubePre
>> into the
>> > >effects loop I am adding to the organ.
>> > >My goals are to make it distorted and really simple.  I want my
>> Hammond
>> >to
>> > >scream :)
>> >
>> >You might consider adding a small push/pull stage with an output
>> >transformer
>> >then,
>> >instead of just building a tube preamp. No power tube required - the
>> sound
>> >is in the
>> >circuit topology, IMO, so you could build something like a 100mW (or
>> even
>> >less)
>> >PP stage from small signal triodes.
>> >
>> >JH.
>> >
>>
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