Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: biker883 on April 06, 2012, 09:05:36 am

Title: 5E3 FOR OTHER USE
Post by: biker883 on April 06, 2012, 09:05:36 am

My first and only amp built is a 5e3 which is perfect and was very easy for me to do it. So, I was wondering if it is possible to build  2 x 5e3 with a big enough common PT in order to use it as a home stereo amp for a tuner & cdplayer. What mod must be done to handle this kind of input?
As soon as you stop laughing, plz reply. Thanks

Title: Re: 5E3 FOR OTHER USE
Post by: jjasilli on April 06, 2012, 11:11:28 am

Usually guitar amps are not desirable for hi-fi use.  One issue is tone - EQ circuitry. Another is that the guitar is a midi-range instrument.  The OT in a guitar amp need not be designed to pass the entire spectrum of audio frequencies from 20Hz - 20,000Hz.  Signal-to-noise ratio acceptable in a guitar amp may be objectionable in a hi-fi amp.  Also, THD (Total Harmonic Distortion - bent wave forms, saturation, compression, harmonics) which are acceptable or even desirable in a guitar amp are a no-no in hi-fi.  In summary, guitar amps are part of the tone generation process.  Hi-fi amps are for reproduction.

My solution to the same desire to apply guitar tube amp skills to hi-fi, was to rebuild vintage PA or hi-fi tube amps.  Some vintage PA amps are good enough for this purpose, and are less expensive.  There's also kits and DIY audio projects available on-line. Lots of info on the web.

Title: Re: 5E3 FOR OTHER USE
Post by: Tsquared on April 06, 2012, 04:35:57 pm

You could always go to Bottlehead.com and build a kit, or build a Dynaco clone from Triode electronics
http://www.triodeelectronics.com/hifikits.html (http://www.triodeelectronics.com/hifikits.html)
There's plenty of support all over the web for those!  Or haunt some estate sales or hamfests for something to rebuild.

Tod

Title: Re: 5E3 FOR OTHER USE
Post by: PRR on April 06, 2012, 11:38:25 pm

> As soon as you stop laughing

Not laughing.

Music reproduction is different from music creation. The playback amp should usually have speaker damping, and maybe lower distortion.

This is easy to do on 5E3.

The PT sold for "36 Watt" (the big brother of the "18 Watt" Marshall) should give reasonable voltages for four small power tubes.

The DeLuxe OT is fine. Leave the primary leads temporarily long. Start-up with the "10K-22K" resistor disconnected. It should play. Connect a 10K resistor. If it HOWWWLs, swap the OT primary leads. It will play softer and more mellow. If too mellow, try 22K.

Title: Re: 5E3 FOR OTHER USE
Post by: biker883 on April 07, 2012, 10:24:56 am

Thanks all for the replies. I have seen the dynaco st70 schematic, and is a lot difficult from the 5e3 and more expensive too. i like PRR's approach...I will give it a try.