Yhanks Mr. vzaichenko.
For file and Such a quick reply, I am here and sharing always what I learn. https://www.facebook.com/vedmitraa
For file and Such a quick reply, I am here and sharing always what I learn. https://www.facebook.com/vedmitraa
XHS - refined, IPS measurements (v3) - many pictures
Coming back for a minute to my relatively old
p) super-symmetric design (January 2014).
Slightly refined schematic and some values - more common mode stability, fine-tuned square wave response.
I was thinking about adding a real CMCL here, but after some practical testing it is clear that helper transistors in LTPs keep the VAS quiescent current stable enough (at around 6.5 mA) - very light fluctuation exists, but at the scale nothing to worry about.
Measurements are performed with IPS only - OPS is temporarily disassembled some time ago.
THD and - more important - IMD are close to my measurement system limits.
Harmonic components are practically masked by noise at around -110db level - this is a virtually "no distortion" IPS.
I will re-assemble OPS soon and re-measure and run listening tests in the nearest future. FUN!
Cheers,
Valery
Coming back for a minute to my relatively old
p) super-symmetric design (January 2014).Slightly refined schematic and some values - more common mode stability, fine-tuned square wave response.
I was thinking about adding a real CMCL here, but after some practical testing it is clear that helper transistors in LTPs keep the VAS quiescent current stable enough (at around 6.5 mA) - very light fluctuation exists, but at the scale nothing to worry about.
Measurements are performed with IPS only - OPS is temporarily disassembled some time ago.
THD and - more important - IMD are close to my measurement system limits.
Harmonic components are practically masked by noise at around -110db level - this is a virtually "no distortion" IPS.
I will re-assemble OPS soon and re-measure and run listening tests in the nearest future. FUN!
Cheers,
Valery
Attachments
Final version - v4
Final update. Removed LTP mirrors, improved compensation.
Measurements are still at the edge of my measurement system capabilities.
Excellent, rock stable, virtually "no distortion" symmetric front-end, using very simple, widely available components.
Very good clipping at 125V p-to-p (see attached).
PCB at standard 4"x3" size will follow soon.
Cheers,
Valery
Final update. Removed LTP mirrors, improved compensation.
Measurements are still at the edge of my measurement system capabilities.
Excellent, rock stable, virtually "no distortion" symmetric front-end, using very simple, widely available components.
Very good clipping at 125V p-to-p (see attached).
PCB at standard 4"x3" size will follow soon.
Cheers,
Valery
Attachments
Test with 2 x Lat-FET pairs OPS (from TubSuMo)
One of the possible combinations. Very natural sound. Excellent stability. 8 ohm load.
One of the possible combinations. Very natural sound. Excellent stability. 8 ohm load.
Attachments
Test with EF + 3 x IRFP pairs OPS (based on SlewMonster PCBs)
Another combination with OPS I have in hand now.
Lower distortion, sounding very close to the previous one.
With all 5 pairs installed, forms a monster-power low distortion amplifier. Distortion growth with amplitude growth - very low dependency.
Still going to re-assemble the original BJT OPS...
Another combination with OPS I have in hand now.
Lower distortion, sounding very close to the previous one.
With all 5 pairs installed, forms a monster-power low distortion amplifier. Distortion growth with amplitude growth - very low dependency.
Still going to re-assemble the original BJT OPS...
Attachments
Hi!
I did test it with the new non-switching OPS - this one:
http://www.diyaudio.com/forums/soli...e-old-ideas-1970s-ips-ops-35.html#post4554894
Measurement results are attached - bode, spectrums 50W @ 8 ohm and square wave responses at 40V p-p.
This front-end needs a new layout - more compact and "standardized" in terms of dimensions and connections. I'm a bit surprised with relatively low interest to it - it's very good. Well - many transistors, but all of them are cheap and easy to buy.
Cheers,
Valery
Attachments
Do you want that i take a look? I just need the schematic with parts rating details...
Marc
Could it be possible to create a ips boards that could match with a slewmaster board like a kypton c or ND does?
Hi Marc, it would be great!
Schematic will be very similar to the one, shown here:
http://www.diyaudio.com/forums/solid-state/248689-xhs-xtra-high-speed-design-5.html#post4098539
I will add/edit a few caps/resistors according to the latest tested prototype and publish the final version here today.
Let's call it XHS 1.1
Cheers,
Valery
Last edited:
Here we go!
Resistors' power ratings:
- diagonal line "/" means 0.25W (like R2);
- horizontal line "|" means 1W (like R4).
Attachments
Marc, very kind of you
Do you have any advice on transistors heatsinking or coupling?
Marc
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