Author Topic: ECH83 tube preamp  (Read 21540 times)

rankot

Re: ECH83 tube preamp
« Reply #60 on: January 31, 2019, 08:49:26 AM »
If you don't need it to overdrive, the tonestack will not make any harm.
Ampegulator, Bassballs, Bazz Fuss, Bearhug Compressor, Bronx Cheer, Clean Sweep, Demeter Compulator, Electra Distortion, Engineer's Thumb, Hybrid Fuzz, Orange Squeezer, ProCo Rat, Ross Compressor, Valvecaster, 6J6, SFT 2, Ugly Face, more to come...

jhsa

Re: ECH83 tube preamp
« Reply #61 on: January 31, 2019, 09:14:20 AM »
True. I need it to boost the signal a bit, and color it nicely, that's it :)

Joćo

rankot

Re: ECH83 tube preamp
« Reply #62 on: February 11, 2019, 03:11:13 PM »
I've been writing to Mr. Derk Reefman, who is one of the guys behind utracer (http://www.dos4ever.com/uTracer3/uTracer3_pag14.html). I was initially asking him about various params for remote cutoff pentode and heptode modelling, and during that discussion, I've sent him a schematic for this preamp. He noted that G3 shall be connected to ground, or to cathode potential (to conserve tube and extend it's life), and not to anode or even worse B+. My question is why? I don't have a book covering heptode, so I must admit my knowledge on this topic is really poor.

« Last Edit: February 11, 2019, 03:16:51 PM by rankot »
Ampegulator, Bassballs, Bazz Fuss, Bearhug Compressor, Bronx Cheer, Clean Sweep, Demeter Compulator, Electra Distortion, Engineer's Thumb, Hybrid Fuzz, Orange Squeezer, ProCo Rat, Ross Compressor, Valvecaster, 6J6, SFT 2, Ugly Face, more to come...

PRR

Re: ECH83 tube preamp
« Reply #63 on: February 11, 2019, 09:32:28 PM »
> G3 shall be connected to ground, or to cathode

At LOW voltage, <12V, I would not worry about it.

And specifically the ECH83... the datasheet says "as RF or IF amplifier" Vg2+g3+g4 can be run at full supply voltage. See also graphs G H I.