Hi Jens,
If you would rotate fuses f3, f4, f5 and f7 for 90° you could put VS and VS1 near c43. It would be easier to make jumper, and smaller mess with wires. Same for VC. In that case you need to put c15 a bit lower.
Well I do not know if some other traces are making this impossible. I like the layout as it is.
Thanks Jens!
If you would rotate fuses f3, f4, f5 and f7 for 90° you could put VS and VS1 near c43. It would be easier to make jumper, and smaller mess with wires. Same for VC. In that case you need to put c15 a bit lower.
Well I do not know if some other traces are making this impossible. I like the layout as it is.
Thanks Jens!
Jens, Do you feel confident enough about this that we can send the gerbers to the board manufacturers. I for one would really like to begin implementing this into an amplifier design with separate regulated frontend supply. I have never been able to listen to such an amp and would like to hear it.
Will this work with the current 10 transistor output or will it have to be a cascode -- series -- design. It looks very neat and well though out. Thanks Tad
Will this work with the current 10 transistor output or will it have to be a cascode -- series -- design. It looks very neat and well though out. Thanks Tad
Bob,
Would you describe or can you provide a block diagram for the use of regulated supplies you would consider? I see there is interest growing for another round of the PSU 2.2 boards.
PSU 2.2
People, please note Jens' caution about the need for someone to step up and prototype the first board. This configuration hasn't been built yet and remains unproven. I'm unqualified and not worthy.
Also note the Wiki for expression of interest includes the remnants of a previous buy. The top section is active and the place to make your entry.
Group Buy Wiki
Would you describe or can you provide a block diagram for the use of regulated supplies you would consider? I see there is interest growing for another round of the PSU 2.2 boards.
PSU 2.2
People, please note Jens' caution about the need for someone to step up and prototype the first board. This configuration hasn't been built yet and remains unproven. I'm unqualified and not worthy.
Also note the Wiki for expression of interest includes the remnants of a previous buy. The top section is active and the place to make your entry.
Group Buy Wiki
Ed -
Referring to the scheatic Jens just posted, the simplest front end regulation scheme would be to connect a regulated supply at ~output rail voltage to VC2/VS2. Then the whole front end would be regulated at the same voltage.
Along the way someone suggested that regulating each stage separately yielded a sonic improvement. You could omit JP2 an JP4 and have separate regulated supplies for the drivers and VAS/differential (using the jumpers as connections) or also remove JP1 and JP 3 and have separate supplies for each stage.
The differential could use a lower voltage than the output rails, which would allow the use of lower voltage rated, higher hfe devices like the BC546C/556C that I have so many of. For bipolar outputs, you want the front end to clip before the outputs so they should have approximately the same rail voltage.
Of course you could regulate the output stage, too, which some say has sonic benefits as well. PSU 2.2 coud not provide enough current, but could drive a bank of higher power devices with a little creativity.
Hope this helps, I don't have a good way to get you a drawing.
Referring to the scheatic Jens just posted, the simplest front end regulation scheme would be to connect a regulated supply at ~output rail voltage to VC2/VS2. Then the whole front end would be regulated at the same voltage.
Along the way someone suggested that regulating each stage separately yielded a sonic improvement. You could omit JP2 an JP4 and have separate regulated supplies for the drivers and VAS/differential (using the jumpers as connections) or also remove JP1 and JP 3 and have separate supplies for each stage.
The differential could use a lower voltage than the output rails, which would allow the use of lower voltage rated, higher hfe devices like the BC546C/556C that I have so many of. For bipolar outputs, you want the front end to clip before the outputs so they should have approximately the same rail voltage.
Of course you could regulate the output stage, too, which some say has sonic benefits as well. PSU 2.2 coud not provide enough current, but could drive a bank of higher power devices with a little creativity.
Hope this helps, I don't have a good way to get you a drawing.
tryonziess said:
Well Tad, I use the "pile displacement" technique... lots of filing boxes from Staples... my "lab" is starting to look like the first scene of a Cold Case episode...
I am also reducing my "collection of eBay offerings" and changing to a PXI-based bench (http://www.diyaudio.com/forums/showthread.php?s=&postid=1413066#post1413066)
tryonziess said:
Well, as soon as I finished the first pair of boards, a friend of mine from overseas came to visit and made an insane offer on them... and I accepted it!
Let me put this way: what he paid was enough to cover my 10 boards and components for at least half of them. We are both happy!
I love the sound of this amp, and I love Jens' design - the best.
All I need is to start working on an enclosure. I have been looking on eBay for "amps for parts" - found a BGW enclosure this week.
I hope to have at least another amp completed before this current group buy gets the new boards ordered. I am in, of course.
Cheers!
Tony made a remark a few posts back concerning the ability to use this new cascode front end without using a cascode output stage. I do not know much about this so what would have to be implemented to use a parallel output -- ie, 10 transistor -- without cascode.
Jens what program do you use to create those realistic board layouts. Tad
Jens what program do you use to create those realistic board layouts. Tad
tryonziess said:
Hello Tad,
yes, if you have the super leach amp board front-end you can still do a lo-tim leach amp.....just don't stuff the parts in for super leach and jumper wires here and there, i know this can raise eyebrows, but i have actually seen this done with the original super leach board...it doesn't take a genius to figure this out...
Tad -
To convert the cascode output to a standard one, mentally remove/jumper the transistors closest to the rails and the resistors associated (R46A, etc.) to create a standard output stage. You'd connect a standard output stage's bases to J1J5 and J1J8, Feedback to J1J6 or J1J7 and protection to J1J4 and J1J9.
To convert the cascode output to a standard one, mentally remove/jumper the transistors closest to the rails and the resistors associated (R46A, etc.) to create a standard output stage. You'd connect a standard output stage's bases to J1J5 and J1J8, Feedback to J1J6 or J1J7 and protection to J1J4 and J1J9.
