mrr3000gt...please read

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bluesbear
Hey get your own solder
Posts: 317
(1/31/04 8:26 am)
  mrr3000gt...please read
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 I just reread my response to you in the "hot switch" thread. At 3 am that seemed perfectly reasonable and polite. Somehow, at 8:30 am, it seems kinda snotty. Maybe it's just me but in case you read it and agree, it wasn't meant to be. Sorry if it sounded that way to you, too.
Actually, I appreciate your response.
Dave
 
mrr3000gt
I will work on all amps
Posts: 361
(1/31/04 9:40 am)
  Re: mrr3000gt...please read
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 Blues:

Sorry! I did not intend on it sounding anything other than one amp guy to another. Im sure your abilities are as good if not better than mine when it comes to this stuff. It was late, and I did have a few (one too many?).

Im not the type to give advise like a pseudo-expert: I hate it when people do that. Programmer forums are the worst. There is always some idiot who thinks he is the reincarnated Bill gates clone and clubs people in the head with 'the right opinion'.

I guess it was the rum that made the overall tone of the email sound different (it happens).
I do like a drink or two on the weekend, so if you read a late night post in broken English from me then you know thats the case!

I guess the only point I was making with the amp was that it might be a pain in the ass to make Dougs mod work in a classic 1959 layout. It might actually be easier to build a drop-in board with the mod and save the old board.

Again, I never intend of being obnoxious: the only time was when that person posted a bunch of ads for his company saying he could beat all Dougs prices. I did let that guy have it nicely.

 
 
bluesbear
Hey get your own solder
Posts: 317
(1/31/04 10:25 am)
  Re: mrr3000gt...please read
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 You DID sound like one amp guy to another... I thought I was the one acting funny........Never mind!
Dave
 
mrr3000gt
I will work on all amps
Posts: 361
(2/1/04 1:21 am)
  Re: mrr3000gt...please read
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 Oh, thats OK! We are all into this sickness called ampbuilding and it has various side effects. For me, its becoming a packrat gear junkie (much to the dismay of my wife).

Gerald Weber calls tube electronics a 'sickness'. I know of a guy in the Chicagoland area with a tube collection of over 400,000 tubes, old radios, sound equipment, and even has his house lit with vaccume lamps from the turn of LAST century!

He carrys telefunk, mullard, and every other type. My amp/stereo building buddies up there have been spending hundreds of dollars on his tubes. One of my friends from there was telling me I needed to stock up on mullard GZ34s at $80.00 each! I can get nearly 10 lesser quality GZ34s for that...


BTW: What was the verdict on the bassman? Are you going to add another stage to it? Honestly, if it was mine and the situation with it was what you described, I probably would work out another gain stage on it to hotten it up. The vintage layout is not that hard to understand, as you could use the Hoffman 1959 layout easily to identify the places to modify.
 
bluesbear
Hey get your own solder
Posts: 318
(2/1/04 9:53 am)
  Re: mrr3000gt...please read
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 "What was the verdict on the bassman? Are you going to add another stage to it?"

I'm definitely adding gain stages (1 or more) to switch in and out. I'll tell you my design reasoning and you tell me if I'm wrong.

1) where to put the extra stage.
Marshall puts the extra gain (and so does Doug's hot switch) before the tone controls. That way, the tone controls don't seem to work very well. If the gain is added AFTER the tone controls, they seem to work fine (Bassman already has one). I'll try it right before the PI.

2) where to put the OD control pot within the gain stage
I think that if the pot is in front of the extra stage, I'd be defeating my purpose by overdriving the stage less rather than controlling the volume level. If the pot is after, there would be no way to control how much OD. I think I'll need 2 pots to pull this off, one before (how much OD) and one after (how loud). I'll try 250k before and 1m after.

Anyway, that's the plan. I'll try it is as, but I suspect I'll probably change the preamp to Super Reverb specs which of course would make the clean a little cleaner. I'll see how I like it either way. Maybe I'll even set it up with 2 relays, the first to go from BFSR to BF Bassman, and the second to go to OD. That's the best part of being retired... the time to mess around with it till it's right. The hard part is having enough to mess around to keep from being bored! Oh, well, I retired in Nov. I'll probably feel a lot diferent in June!
Later and thanks!
Dave
 
mrr3000gt
I will work on all amps
Posts: 362
(2/1/04 2:10 pm)
  Re: mrr3000gt...please read
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 I'd copy whatever everyone does with the Plexi-50, as the 1959 is pretty close.

Re-voicing the preamp stages to be more 'Marshall' would also help pick up extra gain.

The HOffman board design allows for a bassman circuit to be easily modified (from first two stages having the 820/220 thing going on the cathodes).


 
bluesbear
Hey get your own solder
Posts: 320
(2/1/04 7:46 pm)
  Re: mrr3000gt...please read
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 "The HOffman board design allows for a bassman circuit to be easily modified (from first two stages having the 820/220 thing going on the cathodes)."

That's the problem with Doug's and all Marshall type designs. They have at least 2 stages before the tone controls. I like the tone controls early so the actually work. I know that means when you mess with them, you're messing with the gain, but I set them once at the beginning of the night and leave them alone. I think my plan will work. I know the clean part will work. It's almost stock Bassman and if I do change it, it'll be almost stock Super Reverb. I'll play with the OD till I like it, then I'll add the switch bits. The switching is easy enough, I've done at least one relay in 4 or 5 amps.
Wish me luck; I'll start ordering the parts I don't have on hand tomorrow.
I'll let you know how it turns out.
Thanks!
Dave
 
 
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