Bogen CHB-50 and suggested proceedings

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beedoola
Posts: 23
Joined: Sat Feb 16, 2013 5:59 am

Re: Bogen CHB-50 and suggested proceedings

Post by beedoola »

Markusv wrote:For my suggestion, the one half of the 6EU7at the input:

Typically /traditionally there is a 100K resistor connected to the plate of the tube. Then there is a parallel 1.5K resistor/22uf capacitor between cathode and ground.
It will drive the following stage a bit harder for better breakup etc

Please look at typical Fender schematics like say a Bassman or a Deluxe Reverb etc for comparison.
The suggested 33K or 68K grid stopper on the 6EU7 grid is to block unwanted frequencies like radio stations and the like

Markus

Disclaimer- I'm no tech wizard so my explanation may be clumsy
Did you remove the .01 from the plate, and just have the 100k and 150 cap in parallel?

and the 1.5k/22uf on Pin 9 (the cathode) was only done to V1A, right?

I added the schematic with the highlighted part.
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M Fowler
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Location: Walcott ND

Re: Bogen CHB-50 and suggested proceedings

Post by M Fowler »

The 6EU7 is grid leak bias.
beedoola
Posts: 23
Joined: Sat Feb 16, 2013 5:59 am

Re: Bogen CHB-50 and suggested proceedings

Post by beedoola »

So I did the mods Markusv and M Flower suggested: Thanks to you both.

Amp sounds pretty good. Another guy had sent me his augmented CHB-100 schematic and one of his mods was to move the Master volume to right after the 12AX7 stage and before the 6C4. I tried it and it produces lots of gain! very grainy. Cool sound but I'm not sure if I like it.

The amp sounds great right now but I'd like to try and get more gain out of it. Besides cranking it or using a pedal, what might be some other options?
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