Hi Tibi,
I just joined diy TONIGHT and saw your QUAD listing here. I was so fortunate back in the 1970's, in HS and College, to subscribe to the ever outstanding British publication Wireless World. They had EVERYTHING about Quad from articles and reviews I am sure. Back then TIM or TID was becoming the thing to optimize, and many smart contributors - some with Pen Names to protect their employment/security would argue for months in the comments section about which way electrons went or some esoteric things, not as lazy as us Americans in putting pen to paper... QUAD and LEAK were some of the amazing names drom the UK. I bought and built kits of FM Stereo Decoders, an external Dolby units, and an PCB Coll based FM Tuner, and Amplifier modules from Sinclair including a ZX-81. THe are some excellent YouTube Audio Historian videos who retold the history of these famous designers and Audio related companies.
I just joined diy TONIGHT and saw your QUAD listing here. I was so fortunate back in the 1970's, in HS and College, to subscribe to the ever outstanding British publication Wireless World. They had EVERYTHING about Quad from articles and reviews I am sure. Back then TIM or TID was becoming the thing to optimize, and many smart contributors - some with Pen Names to protect their employment/security would argue for months in the comments section about which way electrons went or some esoteric things, not as lazy as us Americans in putting pen to paper... QUAD and LEAK were some of the amazing names drom the UK. I bought and built kits of FM Stereo Decoders, an external Dolby units, and an PCB Coll based FM Tuner, and Amplifier modules from Sinclair including a ZX-81. THe are some excellent YouTube Audio Historian videos who retold the history of these famous designers and Audio related companies.
Hello!
I'll not use this one. It use MOSFET for switching and left/right channel GND is common.
Stef.
Good morning,
I can't test the "clip" because I only have a very small 2x34v 160VA transformer. I tried with a Connex 500W 58v power supply and it doesn't work (probably too much capacitor on the output rail). I'm waiting for a 500VA transformer to do more testing.
I plugged it into a mono speaker this morning. So far, I haven't heard any difference with the Q17-Mini. Always as detailed and beautiful bass control. Maybe a little more "round" like sound than the Mini.
In any case at first sight, it is good for the service. No problem with the measurements and the sound is ok on a speaker.
I have 3 pairs of spare PCBs if anyone is interested.
Stef.
I can't test the "clip" because I only have a very small 2x34v 160VA transformer. I tried with a Connex 500W 58v power supply and it doesn't work (probably too much capacitor on the output rail). I'm waiting for a 500VA transformer to do more testing.
I plugged it into a mono speaker this morning. So far, I haven't heard any difference with the Q17-Mini. Always as detailed and beautiful bass control. Maybe a little more "round" like sound than the Mini.
In any case at first sight, it is good for the service. No problem with the measurements and the sound is ok on a speaker.
I have 3 pairs of spare PCBs if anyone is interested.
Stef.
Hello,
I retested with the Connex SMPS600RxE 60v power supply (set to the minimum, 58v). This power supply works with others amplifier boards.
I'm not sure if the problem comes from the Connex power supply. Unfortunately I don't have a 60v analog power supply to compare.
The voltages are good (58v at input, 53v after Q13 and Q14, 14v at the output of Q1 and Q4, R3 = 774mV and R13 = 660mV). Zero of output DC offset.
The curves are not very telling. If someone has an idea ?
Stef.
EDIT : what about R24 and R25 for 60v?
I retested with the Connex SMPS600RxE 60v power supply (set to the minimum, 58v). This power supply works with others amplifier boards.
I'm not sure if the problem comes from the Connex power supply. Unfortunately I don't have a 60v analog power supply to compare.
The voltages are good (58v at input, 53v after Q13 and Q14, 14v at the output of Q1 and Q4, R3 = 774mV and R13 = 660mV). Zero of output DC offset.
The curves are not very telling. If someone has an idea ?
Stef.
EDIT : what about R24 and R25 for 60v?
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Hello Andrew
I use the speaker protection circuit and the softstart from the forum here and have put the Gerber files on my homepage and the parts lists for it online (also in English): http://lautsprecher.tuschell.de/DIY/Q17_en.html
These work with relays and are tonally neutral and electrically functional.
Regards Tim
I use the speaker protection circuit and the softstart from the forum here and have put the Gerber files on my homepage and the parts lists for it online (also in English): http://lautsprecher.tuschell.de/DIY/Q17_en.html
These work with relays and are tonally neutral and electrically functional.
Regards Tim
Hi Tim,
Two separate ground planes on both sides with a jumper (R32).
Those oscillations at 60v do nothing on the hardware. Lucky!
I'm going to play around with R25 a bit to see what it does.
Anyway at 50v. No problem!
I just need to get a better PSU to make him suffer a bit.
Stef.
Two separate ground planes on both sides with a jumper (R32).
Those oscillations at 60v do nothing on the hardware. Lucky!
I'm going to play around with R25 a bit to see what it does.
Anyway at 50v. No problem!
I just need to get a better PSU to make him suffer a bit.
Stef.
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I tested the board at 56v and it works.
I pulled out a small 230v surge box I had in stock and was able to add 3v to my analog power supply.
The mystery remains intact.
To celebrate, I released the Auricap XO that I had been keeping cool for over a year.
Stef.
I pulled out a small 230v surge box I had in stock and was able to add 3v to my analog power supply.
The mystery remains intact.
To celebrate, I released the Auricap XO that I had been keeping cool for over a year.
Stef.
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Hello!
If you're looking for FQA36P15, I've found some here. Seems to be real FQA36P15 (and matched).
https://www.ebay.fr/itm/323085516549
The FQA46N15 is still available everywhere.
Stef.
Hello Andrew!
Some products, I commonly use for my amp projects.
Stereo model with floating ground:
DX-2
https://fr.aliexpress.com/item/4000419999179.html
https://fr.aliexpress.com/item/1005003142860306.html
https://fr.aliexpress.com/item/4001139578551.html
Great product but some units break when first turned on (quality control). Use 12vAC 6VA transformer. They have just restarted production after 6 months out of stock.
I tried to find other models using this principle of floating ground but I did not find any. It's easy to know: If the GND is common to both channels on the board (same connected connector for the GNDs), it is not good.
Soft start PSS-B
https://fr.aliexpress.com/item/4000420039433.html
Great product, no quality problem. Same designer of the DX-2.
Mono model:
Highend CP-1HC
https://motronix.co.il/product/dcp-...y-for-high-power-current-monoblock-amplifier/
Basic DCP-M1
https://motronix.co.il/product/dcp-...for-mono-block-amplifiers-with-turn-on-delay/
Very good products but shipping is expensive (Israel). Use 12vAC 6VA transformer.
Regards,
Stef.
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Hello,
Some measurements made just below the Q17-Turbo "clip" with a 500vA transformer.
Power DC input: 50v
Signal input: 480mVRMS
Signal output (sinus): 12vRMS (34vPP).
Consumption at 240v: 85W
The behavior of the board seems good.
Stef.
Some measurements made just below the Q17-Turbo "clip" with a 500vA transformer.
Power DC input: 50v
Signal input: 480mVRMS
Signal output (sinus): 12vRMS (34vPP).
Consumption at 240v: 85W
The behavior of the board seems good.
Stef.
