I have started work on another line amp in order to use up the 5692 red base tubes that are sitting on my bench. What I have drawn is mostly by memory(and that it fading). Would you mind taking a look at what I have got and suggest corrections and modifications please? Schematic is drawn in handicad.
I haven't done the PS yet. I do have several transformers. a 250-0-250, and a 370-0-370. I would like to incorporate several regulator tubes to achieve a B+ of 250V.
Thanks
Joe
I haven't done the PS yet. I do have several transformers. a 250-0-250, and a 370-0-370. I would like to incorporate several regulator tubes to achieve a B+ of 250V.
Thanks
Joe
I had the same problem with the schematics that I drew using ISIS. Download a program called IRFANVIEW (a search on google will turn up the address. Open up your schematic with Irfanview and click on IMAGE and then RESIZE/RESAMPLE. Type in 800 in the highlighted square and hit enter. Then click on IMAGE again and then on SHARPEN. You should be able to save the image a post it at this point. When you save the image save it as a Gif. Hope that helps.
G
G
Hi,
If the image is saved and blown up to 200% it is useable.
From what I see you left R7 and R9 undefined, correct?
C3 is 470µF?
C2 is 0.470µF which for most applications will likely be too small.
C1 however will be a little too big once R7 is defined...which is where you have trouble, I assume?
Cheers,
If the image is saved and blown up to 200% it is useable.
From what I see you left R7 and R9 undefined, correct?
C3 is 470µF?
C2 is 0.470µF which for most applications will likely be too small.
C1 however will be a little too big once R7 is defined...which is where you have trouble, I assume?
Cheers,
It has been brought to my attention that there is a similar schematic here in a post that uses a 12sn7 tube with a 300v B+ supply. I would like to use a similar schematic and adapt it to the 5692 tube only since it is more delicate that the 6SN7 is.
I would like a 250 volt B+ maximum I believe. I think that is the limit on the 5692 or close to it. I would like some help with the other values involved. As Frank was good to point out I have several missing R values and several C values that are incorrect.
Frank
I assume that R7 might be around 47K and C2 might be better at 1mfd. I think that R6 and R4 would have to be refigured also.
I will need to drive the 100K input of my Quicksilvers. I'm starting to believe what I was told months ago about not needing much gain.
Joe
I would like a 250 volt B+ maximum I believe. I think that is the limit on the 5692 or close to it. I would like some help with the other values involved. As Frank was good to point out I have several missing R values and several C values that are incorrect.
Frank
I assume that R7 might be around 47K and C2 might be better at 1mfd. I think that R6 and R4 would have to be refigured also.
I will need to drive the 100K input of my Quicksilvers. I'm starting to believe what I was told months ago about not needing much gain.
Joe
Hi,
A rough guess would be about 8V/9V out for 1V in.
I deliberately didn't optimise it for gain since you'll be throwing it away most of the time anyway.
If you need more gain, decouple the first cathode R with a good quality cap and live with the colourations...
Do you need a PSU to go with it?
Cheers,
A rough guess would be about 8V/9V out for 1V in.
I deliberately didn't optimise it for gain since you'll be throwing it away most of the time anyway.
If you need more gain, decouple the first cathode R with a good quality cap and live with the colourations...
Do you need a PSU to go with it?
Cheers,
Franks 5692 line amp
Hi Frank
Thanks for the help. With regard to gain... I have finally become a believer. Mega gain isn't needed in a line amp.
With respect to the power supply... I was going to use a 5Y3, a 370-0-370 transformer, 2) 50 mfd capacitors, 2) 30H chokes@ 40mA 595 ohm and a VR150 and VR90.
I would value your opinion on the usage of the above. I'm kinda stuck on the chokes and regulator tubes now. Its the same supply I am using on the 5687 line amp I have so I assume its beefy enough for the 5692's.
If you would like to help here please go for it.
Thanks
Joe
Hi Frank
Thanks for the help. With regard to gain... I have finally become a believer. Mega gain isn't needed in a line amp.
With respect to the power supply... I was going to use a 5Y3, a 370-0-370 transformer, 2) 50 mfd capacitors, 2) 30H chokes@ 40mA 595 ohm and a VR150 and VR90.
I would value your opinion on the usage of the above. I'm kinda stuck on the chokes and regulator tubes now. Its the same supply I am using on the 5687 line amp I have so I assume its beefy enough for the 5692's.
If you would like to help here please go for it.
Thanks
Joe
Hi,
And you'll still have ample gain to burn...wich will give you lots of dynamics either way of the scale...
Use a tube rectifier if you like but with the advent of the Cree Sics diodes I tend to prefer those, money no object.
Granted the tube rectifier + choke may still win sonically but probably not economically. (Who cares?)
Provided you make this a dual mono PS, I'm confident it has everything to be a world-class pre.
You can still adopt chokes in the PS, I like them there; they make for good isolation between stages but here's the everyman's PS:
The P.S. can be redrawn for choke use, hey, you need to get rid of them 150H Hammonds, right?
Cheers,
And you'll still have ample gain to burn...wich will give you lots of dynamics either way of the scale...
Use a tube rectifier if you like but with the advent of the Cree Sics diodes I tend to prefer those, money no object.
Granted the tube rectifier + choke may still win sonically but probably not economically. (Who cares?)
Provided you make this a dual mono PS, I'm confident it has everything to be a world-class pre.
You can still adopt chokes in the PS, I like them there; they make for good isolation between stages but here's the everyman's PS:
The P.S. can be redrawn for choke use, hey, you need to get rid of them 150H Hammonds, right?
Cheers,
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