Samoloko - There was a buy of the 10 output version posted on Jens' website. This buy sold out.
We are discussing the possibility of a redesign to shorten the feedback path and/or include separate front end and outputs. Whether we get a new design depends on Jens' free time and the availability/willingness of someone to build and test a prototype (any volunteers?) before we can do a group buy.
We may end up with another buy of the original 10 output board. Pricing is yet to be determined but should be under $20 for the original board, slightly higher for either of the new designs.
You can express interest HERE by scrolling to the bottom of the page and clicking on the edit this page link at the bottom. You will have to log in again the first time. Interest shown on the WIKI is not binding if you don't like the version of the board that we end up with you may back out.
We are discussing the possibility of a redesign to shorten the feedback path and/or include separate front end and outputs. Whether we get a new design depends on Jens' free time and the availability/willingness of someone to build and test a prototype (any volunteers?) before we can do a group buy.
We may end up with another buy of the original 10 output board. Pricing is yet to be determined but should be under $20 for the original board, slightly higher for either of the new designs.
You can express interest HERE by scrolling to the bottom of the page and clicking on the edit this page link at the bottom. You will have to log in again the first time. Interest shown on the WIKI is not binding if you don't like the version of the board that we end up with you may back out.
Somoloka, If you are referring to how the finished amp sounds. I like the sound of mine enough to put my Mcintosh mc2250 up for sale on ebay. I think I have a much better amp now with my Leach Clone 10 transistor version. The dynamics and clearity are very good. The amp is dead silent with no turnon or turnoff thump and no noise between musical passages. I am very satisfied . My opinion anyway. Tad
samoloko said:
Hi, I have original design v4.5 low tim amp.
It is much better than all other commercial amps I have heard.
I have put about 200mA bias current per channel (3 pairs of output devices) and I use it on party too
On full power my big heat sinks get warm but I cool them down with fan in that case.
Only amp that is going to heat my system instead of leach are 300b mono blocks ....
Music, nothing else matters…
Where to go from here?
Hi All,
I understand what has been said here and I conclude that people want a front end that allows both the original and super amp option.
This is ok, but what kind of powerstage should I go for? Most likely both the original type and Super amp type will be needed at some point.
Maybe the Super amp redesign and this GB can use the same boards?
Here is a schematic with what I have in mind - comments please
\\\Jens
Hi All,
I understand what has been said here and I conclude that people want a front end that allows both the original and super amp option.
This is ok, but what kind of powerstage should I go for? Most likely both the original type and Super amp type will be needed at some point.
Maybe the Super amp redesign and this GB can use the same boards?
Here is a schematic with what I have in mind - comments please
\\\Jens
DC Dude, When you get your bench cleared off send me some Instructions. I have been trying to get that space cleaned up for 20 years. Every time I think it is organized I start some new project. Keeping up with all of those little parts is rough.
How are your builds going to date? You should have a board or two populated by now. Tad
How are your builds going to date? You should have a board or two populated by now. Tad
Jens,
Could you place jumpers in each rail between the differential and VAS and driver/VAS so that nuts like Jacco and me could separately regulate each stage?
If it could be laid out with a pad for a power connection and we'd have to cut a trace if we wanted to separate the stages would cut down on problems for those not as interested in experiments.
Thanks.
Could you place jumpers in each rail between the differential and VAS and driver/VAS so that nuts like Jacco and me could separately regulate each stage?
If it could be laid out with a pad for a power connection and we'd have to cut a trace if we wanted to separate the stages would cut down on problems for those not as interested in experiments.
Thanks.
Jens. What you have in mind is exactly what I was thinking of when making post #377. I like this version you have posted. Let's use this as the baseline design for the front end. Everything I have read about cascode output stages indicates that they are not very good sounding compared with standard output configurations. My first-hand listening experience confirms this. Nelson Pass, who has designed many amplifiers using cascode output stages, no longer favours them. Given the high voltage output transistors available now, there is really no reason to use a cascode output stage. What about using the front end design you just posted (super amp v5.01) and using a 10+ output stage as used in your previous design. Builders could actually configure their output stages with as many transistors as they wished to. ---HK
Landoctor said:
I agree...
Even though I'm not running the GB, and Tad can ultimately do whatever he pleases, I envision this GB as being 3 boards: A universal frontend, a 10-device Low-TIM output stage, and a 16-device (4 quads) Super Amp output stage.
I don't know if 4 quads is right number for the Super Amp, but that's how Jens drew the schematic.
--Greg
