Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tubenit on September 26, 2009, 01:32:11 pm

Title: 5879 & 6BM8 Champ reverb
Post by: tubenit on September 26, 2009, 01:32:11 pm
Since there seems to be some interest in Champ type amps with reverb, I thought I'd throw this one in the mix.

Preamp is pretty close to the 56T reverb I play but matched to a Champ power section.

I'll try to draw up a layout later and post that also.

I personally prefer the sound of the 6BM8 tube more than an EL84.

With respect, Tubenit
Title: Re: 5879 & 6BM8 Champ reverb
Post by: ampgeek on September 26, 2009, 03:13:45 pm
Very cool as usual Tubenit!

I have been looking closely at your numerous reverb circuits and notice that in some cases the driver and recovery triodes are fed by the same B+ node and in others, a different node.  In one case, a VVR controlled node on the driver side and non-VVR on the recovery side.

What determines your choice?  What does your experience suggest for a VVR implemented plan?

Thanks as always,
Dave O.

 
Title: Re: 5879 & 6BM8 Champ reverb
Post by: tubenit on September 26, 2009, 03:27:27 pm
Quote
In one case, a VVR controlled node on the driver side and non-VVR on the recovery side.

Yikes!  That shouldn't be the case. All the reverb should be on a non-VVR side.

As far as nodes ........ I usually just pick something between node C and node E. With the higher voltage being for the send. Kinda arbitrary really. I've had successful reverbs I liked with such a huge variety of voltages that I don't put alot of thought into it to be honest.

With respect, Tubenit
Title: Re: 5879 & 6BM8 Champ reverb
Post by: Fresh_Start on September 26, 2009, 08:29:31 pm
Way cool idea!  Please keep 'em coming...

Cheers,

Chip
Title: Re: 5879 & 6BM8 Champ reverb
Post by: rzenc on September 26, 2009, 09:06:35 pm
Hey tube! very nice Idea man!!!!! however, I found something that may cause future confusion.... :huh:

EDIT:  thanks for the catch, I corrected that and reposted in my initial post  With respect, Tubenit

With Respect

Best Regards

Rzenc
Title: Re: 5879 & 6BM8 Champ reverb
Post by: rifflicks on September 03, 2013, 11:26:59 am
I really like this idea. and have added it to my list of amps to build....I made up a parts list....I like 1 watt resistors for less noise (imo)
Title: Re: 5879 & 6BM8 Champ reverb
Post by: eleventeen on September 03, 2013, 12:34:17 pm
Wow, that looks like fun.

What is "PAB" near the tone stack?

(I know I am gonna feel really dumb when I get the answer)
Title: Re: 5879 & 6BM8 Champ reverb
Post by: foghornleghorn on September 03, 2013, 01:13:11 pm
Looks interesting! I assume the 22pF cap is a high end cut?

I had forgotten there are combo triodes w/power pentode like the 6BM8. Is it at all like the 7199? I imagine it's much cheaper (that wouldn't be difficult).
Title: Re: 5879 & 6BM8 Champ reverb
Post by: rifflicks on September 03, 2013, 03:15:26 pm
P re  A  mp   B  oost
Title: Re: 5879 & 6BM8 Champ reverb
Post by: tubenit on September 04, 2013, 05:15:21 am
Quote
Looks interesting! I assume the 22pF cap is a high end cut?

I had forgotten there are combo triodes w/power pentode like the 6BM8. Is it at all like the 7199? I imagine it's much cheaper (that wouldn't be difficult).

22p is a high end cut.

Not familiar with a 7199?  I think the 6BM8 has a Marshallish type tone to it. And I greatly prefer it over the EL84 which sounds way too chimey (& harsh) for me.

Here is a tune done yrs ago with a HoSo56 using 6BM8's.   No pedals or effects used. Excuse the mediocre & repetitious playing.

http://www.soundclick.com/player/single_player.cfm?songid=7988948&q=hi&newref=1 (http://www.soundclick.com/player/single_player.cfm?songid=7988948&q=hi&newref=1)

With respect, Tubenit



Title: Re: 5879 & 6BM8 Champ reverb
Post by: kagliostro on September 04, 2013, 02:46:02 pm
5879 + 6BM8 Champ

I like your idea (also without reverb)  :thumbsup:

Franco

Title: Re: 5879 & 6BM8 Champ reverb
Post by: Fresh_Start on September 06, 2013, 09:43:03 pm
How about using two 6BM8s, with one pentode section driving the reverb and the other pentode section as the power tube?  IIRC there's a manufacturer's schematic showing this tube used for reverb driver and recovery stages.

Cheers,

Chip
Title: Re: 5879 & 6BM8 Champ reverb
Post by: DummyLoad on September 06, 2013, 11:14:39 pm
How about a 6gw8 for the final and driver  a 6bm8 for reverb and recovery and a 6av6 5879 for the 1st amp.

-pete