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previous: Bjorn Hello to ya all Ampagers!I’... -- 4/6/2000 7:57 PM

Re: More gain in a BF DR

4/6/2000 11:48 PM
Carl Z	Re: More gain in a BF DR Bjorn; I'm not so sure using the DR power tranny is such a good idea. If you want to make sure run the amp HARD for about half an hour to an hour. The transformer should be warm to the touch but not hot. If it fails, don't say I didn't warn you! Gain wise, you're probably at the limit of what you can do with this amp without really tearing into it and reworking every mother loving thing! Here's a few things to try. First ignore that post about the pulling the trem tube. The easiest thing is to sub out the 12AT7 driver tube and replace it with a 12AX7. That'll give you a good kick in the pants alone. The only problem here is that with an AX7 your amp may start to sound a little farty. The cure for that is to replace the 220k grid leak resistors with 100k values. Also change the coupling caps from the driver tube to 0.047uF. That should tighten up the bottom end and should really get your Deluxe pumping! If you think this is a little too much gain then you can put the 12AT7 back in and leave the internal changes in place. While you're under the hood, you might want to consider changing the 470 ohm screen resistors to 1k 5 watts. This won't affect the tone but it's a reliablility upgrade. If that doesn't scratch the itch nothing will! Regards; Carl Z Summit Amps

4/6/2000 11:48 PM

Carl Z

Re: More gain in a BF DR

Bjorn;

I'm not so sure using the DR power tranny is such a good idea. If you want to make sure run the amp HARD for about half an hour to an hour. The transformer should be warm to the touch but not hot. If it fails, don't say I didn't warn you!

Gain wise, you're probably at the limit of what you can do with this amp without really tearing into it and reworking every mother loving thing! Here's a few things to try.

First ignore that post about the pulling the trem tube.

The easiest thing is to sub out the 12AT7 driver tube and replace it with a 12AX7. That'll give you a good kick in the pants alone. The only problem here is that with an AX7 your amp may start to sound a little farty. The cure for that is to replace the 220k grid leak resistors with 100k values. Also change the coupling caps from the driver tube to 0.047uF. That should tighten up the bottom end and should really get your Deluxe pumping!

If you think this is a little too much gain then you can put the 12AT7 back in and leave the internal changes in place.

While you're under the hood, you might want to consider changing the 470 ohm screen resistors to 1k 5 watts. This won't affect the tone but it's a reliablility upgrade.

If that doesn't scratch the itch nothing will!

Regards;
Carl Z
Summit Amps

Replies:

Bjorn Thank you John, Bruce and Carl. You... -- 4/7/2000 11:42 AM