home *** CD-ROM | disk | FTP | other *** search
- Xref: sparky sci.electronics:20551 rec.audio:16579 alt.guitar:10809 rec.music.makers.guitar:872
- Newsgroups: sci.electronics,rec.audio,alt.guitar,rec.music.makers.guitar
- Path: sparky!uunet!cs.utexas.edu!torn!watserv2.uwaterloo.ca!watdragon.uwaterloo.ca!rblander
- From: rblander@watdragon.uwaterloo.ca (Robyn Landers)
- Subject: Re: Tube amp transformers
- Message-ID: <Bz4FK9.Fx3@watdragon.uwaterloo.ca>
- Summary: swapping 6L6 for 6V6 etc
- Keywords: tubes transformers
- Organization: University of Waterloo
- References: <Bz0GpF.Fyn@hfglobe.intel.com>
- Date: Sat, 12 Dec 1992 00:48:09 GMT
- Lines: 37
-
- In article <Bz0GpF.Fyn@hfglobe.intel.com> dcovell@hfglobe.intel.com (David Covell) writes:
- >
- >I recently bought an old tube hi-fi amp that I'd like to cannabilize for
- >parts with which to build a project guitar amp. Several people have told
- >me that hi-fi output transformers aren't suitable for instrument amps.
- >I'd like more data on this; if the problem is that hi-fi output transformers
- >can't handle the saturation that guitar amps put out, can I avoid this by
- >using output tubes of lower power?
-
- From what I understand the problem is the other way around.
- Guitar amp xformers are crappy by hi-fi audio standards. Harry Kolbe
- of Kolbe Soundsmith in NYC told me Marshall xformers in particular
- are really awful from an audio standpoint. (This in relation to
- discussion of why Power Soaks are so evil.)
-
- >The amp uses a pair of 6L6's in each
- >channel. Is there some reason I couldn't use EL84's or 6V6's, which would
- >cut the power by at least 40%? This would avoid output wattage in excess of
- >the transformer's rating, which is the only potential problem I can see with
- >using these transformers. Am I missing something obvious here?
-
- Check that the smaller tubes can handle the plate voltage the xformer
- was providing to the larger tubes. RCA Receiving Tube Manual says
- 6L6 can take 360 volts (design centre), or 500 volts (design maximum)
- at the plate. 6BQ5 (EL84) says 300V design centre; it doesn't
- list design max. You'll want to check plate (and grid etc.) voltages
- that the circuit you're using is providing.
-
- I've been thinking of building/converting an amp to EL84 too...
- ...dare I hack on my nice old Marshall? :-)
-
-
- -----
- Robyn Landers
- rblanders@math.uwaterloo.ca
- "I'm just doing my rock'n'roll duty." -- Dubois
-
-