Dave Hunter's Champ Had it working, had to mess with it

CrackRockert

CrackRockert

New Member
So this was my first (after three rebuilds) amp I got to work.
Used some vintage components, sounded better than my peavy delta blues.

Was more excited then a kid on Christmas, or getting let out of county.

Added a NFB, sounded better!

Then I went on ebay started buying Astors, old USSR stock, so I decided to mod a bit.

All went south, rebuild the board, now I have it working except past 3/4ish volume it starts MBing like the first decent spring day in Wisconsin.

Please understand I just started doing this hobby like 6 months ago, I got the Hoffman Bassman to work recently, no kit just his design.

So I am capable, but explain like I am I dunno, 12?

If anyone has any suggestions, please please I am all ears.
 

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I would not use old "Astors" ? not sure what that is. Do you mean "Astrons" ? old capacitors are probably very leaky and will cause you lots of problems. Also, I have found lots of USSR Capacitors to be bad as well. Use new Parts unless you can properly test them at the working voltages.
 
But its fun to experiment, and yes that is what I meant. I mean maybe, but surely not all. What do you think I should try to stop the motorboarding?
Or was this just tisktisking?
 
Replace the old Capacitors with new ones. For a vintage Fender vibe I prefer CDE Orange drops model 6PS capacitors. Available at Antique Radio Supply. They are constructed very similar to the Vintage Astrons, but with Reliability.

Capacitors - Orange Drop, 600V, Polyester | Amplified Parts

Capacitors - Orange Drop, 600V, Polyester - Rated for 85°C operation. Polyester film capacitor with radial leads. ± 10% tolerance. Features a long history of proven reliability, a low dissipation factor, excellent stability, and a virtually linear temperature coefficient.
www.tubesandmore.com www.tubesandmore.com
 
Jeeze is everyone so persnickety?
Considering the context of my post and the forum itself I thought using initialisms would be fine!
No the connections are true, each B+ is to its proper stage....
Thank you though...
 
billyz said:
Replace the old Capacitors with new ones. For a vintage Fender vibe I prefer CDE Orange drops model 6PS capacitors. Available at Antique Radio Supply. They are constructed very similar to the Vintage Astrons, but with Reliability.

Capacitors - Orange Drop, 600V, Polyester | Amplified Parts

Capacitors - Orange Drop, 600V, Polyester - Rated for 85°C operation. Polyester film capacitor with radial leads. ± 10% tolerance. Features a long history of proven reliability, a low dissipation factor, excellent stability, and a virtually linear temperature coefficient.
www.tubesandmore.com www.tubesandmore.com
Click to expand...
Before I do that, I mean I can test for leaking right?
Ill look it up.....
 
I believe the Dave Hunter amp design you are referring to is his " Two Stroke" .
 
Last edited:
billyz said:
Replace the old Capacitors with new ones. For a vintage Fender vibe I prefer CDE Orange drops model 6PS capacitors. Available at Antique Radio Supply. They are constructed very similar to the Vintage Astrons, but with Reliability.

Capacitors - Orange Drop, 600V, Polyester | Amplified Parts

Capacitors - Orange Drop, 600V, Polyester - Rated for 85°C operation. Polyester film capacitor with radial leads. ± 10% tolerance. Features a long history of proven reliability, a low dissipation factor, excellent stability, and a virtually linear temperature coefficient.
www.tubesandmore.com www.tubesandmore.com
Click to expand...
ONE IS LEAKY!
One Astron leaking like a it got stabbed!
 
Also you know the idea behind using vintage parts is that a lot of people like about the old tube sound is the sway and drag of values, the materials are different.
There is something to be said for that and putting up with a bum part.
 
CrackRockert said:
Also you know the idea behind using vintage parts is that a lot of people like about the old tube sound is the sway and drag of values, the materials are different.
There is something to be said for that and putting up with a bum part.
Click to expand...
I have used many old parts, But They must be tested first. For capacitors you must test them at the rated voltage. Also, I seldom use Used vintage parts. They were most likely pulled because the were bad. Astrons are known to go bad over time. The Fender Blue Molded caps however are Seldom bad.
 
billyz said:
Replace the old Capacitors with new ones. For a vintage Fender vibe I prefer CDE Orange drops model 6PS capacitors. Available at Antique Radio Supply. They are constructed very similar to the Vintage Astrons, but with Reliability.

Capacitors - Orange Drop, 600V, Polyester | Amplified Parts

Capacitors - Orange Drop, 600V, Polyester - Rated for 85°C operation. Polyester film capacitor with radial leads. ± 10% tolerance. Features a long history of proven reliability, a low dissipation factor, excellent stability, and a virtually linear temperature coefficient.
www.tubesandmore.com www.tubesandmore.com
Click to expand...
Also not going to lie, kind of started collecting them like pokemon cards..... had a bit of an ebay shopping spree
 
billyz said:
I have used many old parts, But They must be tested first. For capacitors you must test them at the rated voltage. Also, I seldom use Used vintage parts. They were most likely pulled because the were bad. Astrons are known to go bad over time. The Fender Blue Molded caps however are Seldom bad.
Click to expand...
Oh and I do test them for values at least.....
 
billyz said:
I have used many old parts, But They must be tested first. For capacitors you must test them at the rated voltage. Also, I seldom use Used vintage parts. They were most likely pulled because the were bad. Astrons are known to go bad over time. The Fender Blue Molded caps however are Seldom bad.
Click to expand...
Oh and the Astros are clearly NOS, the leads are pristine
 
Damn it still sounds like an idling jeep past 3/4.

The same .022 that goes to plate a pin 6 on the 12ax is showing the same "leaking" as the one I replaced the likely hood of that seems small.

Both sides show OL to ground in mv..... which is how I am testing leak.....

If anyone else has ideas, I am sitting here with my finger on the power of the soldering iron.....
 
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