Might think about placing the two RCA inputs next to each other, you can reduce the loop area that way. Also allows you to connect both signal grounds, to also reduce loop area.
I believe HRDSTL is building a dual mono psu, in that case you wouldn't want to connect the input grounds together.
Today I got 2,5mm2 cables from aliexpress, hard clumsy, ...they ended up in the trash.
So I ordered Mogami 2919 (6x 2,5mm2), proven quality. I have to strip them of the outer wrapper, and they will be twisted. I'll probably use the black and red for speaker output. The rest will be used for the power supply part.
For the signal part I ordered MOGAMI 2514 in several colors and I will either make a version with two twisted wires together or I will use a high quality shielded MOGAMI 2803 (I have this one at home).
So I ordered Mogami 2919 (6x 2,5mm2), proven quality. I have to strip them of the outer wrapper, and they will be twisted. I'll probably use the black and red for speaker output. The rest will be used for the power supply part.
For the signal part I ordered MOGAMI 2514 in several colors and I will either make a version with two twisted wires together or I will use a high quality shielded MOGAMI 2803 (I have this one at home).
Many of us on DIYA use “RC Drone / Helicopter” battery wire for amp projects. It’s very high strand count copper wire that has heat resistant soft silicone insulation. Designed for high current situations and places very little mechanical strain on joints since so flexible. Available like tap water due to $B drone industry.
For example:
16 Gauge Silicone Wire Spool 50 Feet, Ultra Flexible High Temp 200 deg C 600V 16 AWG Stranded Wire with 252 Strands of Tinned Copper Wire, 25 ft Black and 25 ft Red Wire for Model Battery by MILAPEAK https://a.co/d/4iKU1fm
And
BNTECHGO 16 Gauge Silicone Wire Kit 10 Color Each 25 ft Flexible 16 AWG Stranded Tinned Copper Wire https://a.co/d/8Rfsfeh
For example:
16 Gauge Silicone Wire Spool 50 Feet, Ultra Flexible High Temp 200 deg C 600V 16 AWG Stranded Wire with 252 Strands of Tinned Copper Wire, 25 ft Black and 25 ft Red Wire for Model Battery by MILAPEAK https://a.co/d/4iKU1fm
And
BNTECHGO 16 Gauge Silicone Wire Kit 10 Color Each 25 ft Flexible 16 AWG Stranded Tinned Copper Wire https://a.co/d/8Rfsfeh
The last DIY amp one builds is always the best until the next one. 🙂
Not having heard the Q17 before, but seeing its topology and measurements I would say it probably sounds excellent. It has 17 actives, and one of them a state of the art opamp (with probably 24 transistors in itself) vs the FH9HVX which has 9 actives and no opamp. Much simpler build and less expensive.
From pure THD performance standpoint, I would guess Q17 distortion figures will be superior.
But listening enjoyment has a lot to do with the harmonic profile, phase flatness, amount of negative feedback used, and other immeasurable things like foot tapping rhythm and speed.
I will say that the FH9HVX has some nice smashing bass authority and is a very dynamic and fun sounding amp that works with all music genres.
Looking forward to Vunce’s listening impressions.
Not having heard the Q17 before, but seeing its topology and measurements I would say it probably sounds excellent. It has 17 actives, and one of them a state of the art opamp (with probably 24 transistors in itself) vs the FH9HVX which has 9 actives and no opamp. Much simpler build and less expensive.
From pure THD performance standpoint, I would guess Q17 distortion figures will be superior.
But listening enjoyment has a lot to do with the harmonic profile, phase flatness, amount of negative feedback used, and other immeasurable things like foot tapping rhythm and speed.
I will say that the FH9HVX has some nice smashing bass authority and is a very dynamic and fun sounding amp that works with all music genres.
Looking forward to Vunce’s listening impressions.
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As X has eluded to, I'm still in the Q17 honeymoon phase, latest is greatest 🤣.
But, in general I'm not really a good reviewer that uses audiophile hyperbole. What I will say is both amplifiers are definitely worthy of building so you can hear them in your own room with your supporting gear. I know these comments are not what you're looking to hear, but as they say, Build them All!!
Hi.
Almost done the new chassis with big heatsinks l, just waiting on thermal pads then I can mount the new FETs..
Cheers.
Almost done the new chassis with big heatsinks l, just waiting on thermal pads then I can mount the new FETs..
Cheers.
It's alive!
I must say the IRFP FETs are much nicer from a mechanical point. There are no sharp edges on the backside like the FQA devices.
Shooting for 44mV or 200mA bias.
Cheers.
Nik
I must say the IRFP FETs are much nicer from a mechanical point. There are no sharp edges on the backside like the FQA devices.
Shooting for 44mV or 200mA bias.
Cheers.
Nik
Nice, ...personally, I would not put the transistor for temperature stabilization over wires, as it is very close to the power mosfets.
32 mv DC offset?
32 mv DC offset?
I have a feeling that DMM reading is across the current source resistors. See how the leads swing back into the enclosure.
Best,
Anand.
Best,
Anand.
Yes, but remember he said he was “shooting for” 200mA bias, which means he was in the process of reaching that value (at the time the picture was taken 😉).
Best,
Anand.
HI.
Yes, still in the calibrating stage.
I have had the amp running for 6 months before and then the FQA on the left channel went POOF for some reason. Now I'm running the IRFP as the FQA are end of life... I also used much bigger heatsinks now,
I love this amp, very dynamic sounding, strong base. Suits me perfectly...
Best of all I am able to repair it and it still cost me less than a low/mid end commercial amp. (Yamaha Pure Direct anyone?😏)
Regards.
Nik
Yes, still in the calibrating stage.
I have had the amp running for 6 months before and then the FQA on the left channel went POOF for some reason. Now I'm running the IRFP as the FQA are end of life... I also used much bigger heatsinks now,
I love this amp, very dynamic sounding, strong base. Suits me perfectly...
Best of all I am able to repair it and it still cost me less than a low/mid end commercial amp. (Yamaha Pure Direct anyone?😏)
Regards.
Nik