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RCA console amp RS193D...

knockbill said:
...
Think I'll put in a switch, and a couple sets of input jacks, and let it live as God intended!!! Its the only 6BQ5 SE amp I have, and is pretty impressive...
This is the reason I have so much trouble finding iron, I guess!!!!!
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Yes, it is hard to gut something that, for a little work, can be made to work well. I would have done the same thing, to fix it up.

Single ended amps do sound good. And give me plenty of power, as I don't blast my music anyway.
 
Yep,,, Think I'll leave the tone controls alone also,,, I turned most amps I've worked on into power amps, this can be a little integrated,,, I have a nice Maple box with dovetailed joints, that fits this chassis well....
And the hunt for iron continues!!

Regards,
John
 
Sometimes its fun to play with "cheap" amps that do better than expected. Its sometimes amazing how good they can sound, despite not being anywhere close to high end gear.
 
gadget73 said:
Sometimes its fun to play with "cheap" amps that do better than expected. Its sometimes amazing how good they can sound, despite not being anywhere close to high end gear.
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Yep,,, Its all about how they sound,,, On the other hand I'm glad I didn't hesitate grabbing the OPTs from that trashed Pioneer,,, I keep getting them for the iron, but this one is just too sweet to strip...

Regards,
John
 
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and hence why I'm glad you got the Pioneer. I' have been spending too much effort on making it work in it's original configuration.
 
you had 1st refusal!!! And I still have the bracket here for ya! That Pioneer is down the road, I didn't have any tubes for it, and even if I got it working, it was too ugly to to be out in public!

Regards,
John
 
Been working on this little amp,,, added a switch and a couple pair of input jacks,,, noticed a 1M resistor across the input leads that isn't on teh schematic,,,, I read someplace, about tying the inputs together, but can't find it now... Whats the advantage, or not of using that resistor?
Thanks,

Regards,
John
 
I'm not sure as I have never owned an RCA stereo tube amp such as the one you have, but I think I remember reading somewhere that your amp can be used in either mono or stereo configuration and that the inputs or outputs are wired out of phase for mono operation or something like that. This might explain the resistor. :dunno:
 
cademan said:
I'm not sure as I have never owned an RCA stereo tube amp such as the one you have, but I think I remember reading somewhere that your amp can be used in either mono or stereo configuration and that the inputs or outputs are wired out of phase for mono operation or something like that. This might explain the resistor. :dunno:
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Well, there isn't a mono-stereo switch on it... just bugs me that I saw it mentioned someplace, and, I'm gettin to old to remember where!!!!

Regards,
John
 
I don't think they normally had a mono/stereo switch. The one RCA amp that I am thinking about is probably the 6V6 version.

I saw something somewhere where the 6V6 version could be wired in either mono push/pull or SE stereo but not sure if yours can be wired the same way. :scratch2:
 
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OK,,, I have a Philco that had a switch to sum the inputs,,, I got caught up working on this guy, after I heard it,,, Extended the chassis to cover the OPTs, and provide a rear panel for input/speaker jacks, fuse holder and power switch...
These little SE amps really get addicting!

Regards,
John
 
knockbill said:
Been working on this little amp,,, added a switch and a couple pair of input jacks,,, noticed a 1M resistor across the input leads that isn't on teh schematic,,,, I read someplace, about tying the inputs together, but can't find it now... Whats the advantage, or not of using that resistor?
Thanks,

Regards,
John
Click to expand...

Figured out teh 1M resistor,,, It sums the two channels somewhat, in that when only one input is plugged in, it still feeds both channels... I removed it, for more separation,,,can't see that it will hurt anything, and sounds better with speakers that are 8'+ apart, rather than in the same box, like the console...

Regards,
John
 
Build a case for it, just has a coat of stain, no finish yet... still needs a new line cord, and some resistors, but its coming along...

Regards,
John
 

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Still fooling with this guy,,, it really sounds good, it's playing thru a pair of Maggy console speaker cabs, But I have a question, the bass control has a lot of range, flat to thumping bass, however the volume increases with as the bass pot is increased... also the treble control doesn't seem to have as much range as the bass...
Is that normal for this circuit? I was thinking of removing the tone stacks, but wanted to experiment with tone controls...
Any input is welcome...
Thanks

Regards,
John
 

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I believe that if you were to inject a signal at the center lugs on the volume pot, you would bypass the tone controls. Try using an external or extra preamp if you have one and hear how it sounds.

EDIT: You might not have enough gain at the center lugs so you could inject a signal directly at pins 5 & 8 of the 6EU7 tube, and then attach both of the .047 capacitors (C203 & C205) directly to pins 2 on both the 6BQ5 tubes. This should bypass all tone controls.
 
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I did inject signal past the tone controls, sounds OK,,, I just wondered about teh volume going up/down somewhat with bass control... Thought I'd try an amp with tone stacks...

Regards,
John
 
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