philips el6400 tubeamp

[Tekko]

Hello!

What is needed to be changed to make a guitar amp out of a Philips EL6400 tube amplifier ?

 

[Tekko]

I have hooked the amp up on one of the mic inputs to the computer cd-rom unit as source nad i must say it sounds really good.

Heres some pics of the amp:

Crappy top view [IMGDEAD]http://user.faktiskt.se/Tekko_Tubeamp/Tubeamp/Tubeamp%20top%20view.JPG[/IMGDEAD] Front view [IMGDEAD]http://user.faktiskt.se/Tekko_Tubeamp/Tubeamp/Tubeamp%20front.JPG[/IMGDEAD] Side view [IMGDEAD]http://user.faktiskt.se/Tekko_Tubeamp/Tubeamp/Tubeamp%20side.JPG[/IMGDEAD] Underneath left [IMGDEAD]http://user.faktiskt.se/Tekko_Tubeamp/Tubeamp/Tubeamp%20underneath%20left.JPG[/IMGDEAD] Underneath right [IMGDEAD]http://user.faktiskt.se/Tekko_Tubeamp/Tubeamp/Tubeamp%20underneath%20right.JPG[/IMGDEAD] And the marking plate [IMGDEAD]http://user.faktiskt.se/Tekko_Tubeamp/Tubeamp/Tubeamp%20marking.JPG[/IMGDEAD]

 

[Fuling]

I´ve owned two EL6400´s, and I have a schematic somewhere.

 

[Fuling]

Here´s some info:

http://johnsplace.homelinux.net/projexp.htm

 

[Tekko]

I have the schemo but thanx anyway. What does irt take to turn this thing into a guitar amplifier ? About what plate to plate impedance is the OPT, around 5-10k ? The amp i have here uses EF86, not EF40 as in the schemo.

 

[Tekko]

This amp got a problem, it starts distorting early when volume is not even loud. What can the problem be ?

 

[EC8010]

Goodness, this amplifier was made before safety was invented!

Seriously, get rid of those selenium HT rectifiers. When they expire, they have a nasty habit of taking the mains transformer with them. Measure the HT before removing them, then replace them with silicon diodes (1N4007), and if necessary, add a little series resistance between the transformer and the rectifier to restore the correct HT voltage.

 

[Tekko]

EC, i´d love to but the amp is not mine. B+ in the thing is 307-310V, screen voltage to the EL81 tubes is about 152v, bias is about -27v and the feed to the preamp tubes is around 157 volts.