A recommendation from me: the sonic influence of the capacitors is clearly audible in the amplifier and that also in the area of voltage stabilization. Therefore, this effect will be much more audible than particularly high quality resistors. I do not want to discourage you from buying such resistors, only I can tell that the condesors applied by Tibi limit the amplifier so much that there is clearly more potential here.
Mundorf is a seller of audio capacitors. This dealer / brand also has very good products, but especially a very good marketing.
I mean physically high quality capacitors.
Example: Tibi uses 100nF metal vaporized polyester film - MKS - for pulse current supply of the opamp, I use 33nF metal foil polypropylene capacitor - FKP - and with it the opamp plays audibly cleaner.
Therefore, capacitors do not necessarily require expensive brands, but suitable designs that are also available at an affordable price.
I mean physically high quality capacitors.
Example: Tibi uses 100nF metal vaporized polyester film - MKS - for pulse current supply of the opamp, I use 33nF metal foil polypropylene capacitor - FKP - and with it the opamp plays audibly cleaner.
Therefore, capacitors do not necessarily require expensive brands, but suitable designs that are also available at an affordable price.
Hey, guys,
Which would you recommend for the C7 position as the best quality/price ratio?
1. Amtrans AMCG Metalized - 10€ /piece
2. Mundorf MCap EVO Oil - 12,5€ /piece
3. Auricap XO Capacitor - 16,5€ /piece
4. Mundorf MCap EVO Silver Gold Oil - 29,6€ /piece
Thank You!
Which would you recommend for the C7 position as the best quality/price ratio?
1. Amtrans AMCG Metalized - 10€ /piece
2. Mundorf MCap EVO Oil - 12,5€ /piece
3. Auricap XO Capacitor - 16,5€ /piece
4. Mundorf MCap EVO Silver Gold Oil - 29,6€ /piece
Thank You!
My tests have shown that an MKP, no matter what quality, is not sufficient to achieve the possible quality of the amplifier.
Therefore, I recommend a combination of MKP and Wima FKP1.
The following sounds particularly good and is very cheap: 1000nF MKP10 and 100nF FKP1. The fact that this combination is 10% larger than the nominal value has no relevant influence on the circuit.
Therefore, I recommend a combination of MKP and Wima FKP1.
The following sounds particularly good and is very cheap: 1000nF MKP10 and 100nF FKP1. The fact that this combination is 10% larger than the nominal value has no relevant influence on the circuit.
Today final soldering, just waiting for connectors (power DC, input) and Miflex capacitor, ...same type as used by Danzup.
I'm also thinking about the power supply, ...
These two Q17's will be powered by an 800W toroid from Toroidy.pl in the audio version + 6x 22.000 uF. I will use a board for the source from home stock, CRCRC from prasi where R will be replaced by jumpers from the bottom side.
I'm also thinking about the power supply, ...
These two Q17's will be powered by an 800W toroid from Toroidy.pl in the audio version + 6x 22.000 uF. I will use a board for the source from home stock, CRCRC from prasi where R will be replaced by jumpers from the bottom side.
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Just confirmed to myself that FQA46N15 & IXTH48P20P make a better pair. Both have almost same Vgs(threshold) and transconductance.
Bass is deeper and amplifier get more control at any volume.
Another nice discovery are Wurth Electronic electrolytics. I like them a lot. To my ears, they sound better than anything I have used so far in this position.
Bass is deeper and amplifier get more control at any volume.
Another nice discovery are Wurth Electronic electrolytics. I like them a lot. To my ears, they sound better than anything I have used so far in this position.
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I still need to build mine, thinking it might be the next build as I already have the amp and psu boards from you. Good to know about the Wurth capacitors, I've had good luck with other products of theirs, they tend to have nice specs.
1 channel ready, worked on first power on. Current through R10 - 66mA. DC offset less than 1mV
Just to test the sound, but I think I'll be satisfied! 😉
Just to test the sound, but I think I'll be satisfied! 😉
Gentlemen!
I would like to ask you for information on the following matter.
I accidentally had the circuit boards for the Q17 Turbo made with 1 oz instead of 2 oz as specified.
Can I still use the boards? Can they stand it? Or do I have to have another one made?
Please help
Zoltan
I would like to ask you for information on the following matter.
I accidentally had the circuit boards for the Q17 Turbo made with 1 oz instead of 2 oz as specified.
Can I still use the boards? Can they stand it? Or do I have to have another one made?
Please help
Zoltan
First of all, thanks to the designer: gorgeous work of engineering at the service of DIY community!
I've read most of the thread and I'm evaluating to build this amplifier; in these days, I'm analysing the used components and, since I've a matched octet of unused IRFP240/IRFP9140 in my drawer, I'm evaluating if I can use it (or not). In my experience, the P Mosfet, 100V rated is a good match with N-Mos 200V in terms of Vgs and transconductance (better than the IRFP9240) and I could/can hear the difference (not much but it's there) in a pair of amplifiers I built in the past.
In this case, the power supply in my hands will be +/-48V under light load, a little lower with high load, but I'm worried about the use of 100V IRFP9140 since the max voltage is quite low in relation to the power supply voltage.
Any comments or advice about it? Could the Vds voltage of P mosfet be higher that the its max allowable level (100V)?
Thanks in advance for any comments
I've read most of the thread and I'm evaluating to build this amplifier; in these days, I'm analysing the used components and, since I've a matched octet of unused IRFP240/IRFP9140 in my drawer, I'm evaluating if I can use it (or not). In my experience, the P Mosfet, 100V rated is a good match with N-Mos 200V in terms of Vgs and transconductance (better than the IRFP9240) and I could/can hear the difference (not much but it's there) in a pair of amplifiers I built in the past.
In this case, the power supply in my hands will be +/-48V under light load, a little lower with high load, but I'm worried about the use of 100V IRFP9140 since the max voltage is quite low in relation to the power supply voltage.
Any comments or advice about it? Could the Vds voltage of P mosfet be higher that the its max allowable level (100V)?
Thanks in advance for any comments
@HRDSTL I would love to hear your first listening impressions.
@ZoltanKl 1oz is very OK and amplifier will perform very well. @stef1777 did a great job and designed an exceptional PCB, so go for it.
@touchdown IRFP240/IRFP9140 are not my preferate mosfet transistors, but if you intend to evaluate amplifier capability, than these are a good start.
IRPF9140 will work just fine. However is far, far, far, far, far, ... by far away from recommended FQAxxxx series.
I'm sure you will love it and later invest more. This amplifier will change your life. No joking.
@ZoltanKl 1oz is very OK and amplifier will perform very well. @stef1777 did a great job and designed an exceptional PCB, so go for it.
@touchdown IRFP240/IRFP9140 are not my preferate mosfet transistors, but if you intend to evaluate amplifier capability, than these are a good start.
IRPF9140 will work just fine. However is far, far, far, far, far, ... by far away from recommended FQAxxxx series.
I'm sure you will love it and later invest more. This amplifier will change your life. No joking.
Hello everyone,
Just to let you know that my amp is progressing slowly. I finally received the chassis. I will have a lot of work. I have 42 holes to make, 22 of which need to be tapped. I gave in and ordered a device to do the tapping automatically.
The sequel to the next episode.
Stef.
Just to let you know that my amp is progressing slowly. I finally received the chassis. I will have a lot of work. I have 42 holes to make, 22 of which need to be tapped. I gave in and ordered a device to do the tapping automatically.
The sequel to the next episode.
Stef.
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@iTiberius: thank you for your enthusiasm and your advice.
Do you suggest the couple FQA46N15 is IXTH48P20P, even though not matched? The IXYS is really espensive to think about matching a bunch of them and I cannot find any P mos of FQAxx series in the e-market (in general, quite less expensive).. my bad.
For sure I'll test the IRFP ones, but I cannot see and find many alternatives in the MOS market in these days ...
Do you suggest the couple FQA46N15 is IXTH48P20P, even though not matched? The IXYS is really espensive to think about matching a bunch of them and I cannot find any P mos of FQAxx series in the e-market (in general, quite less expensive).. my bad.
For sure I'll test the IRFP ones, but I cannot see and find many alternatives in the MOS market in these days ...
Hi Touchdown,
These Fairchild FQA36P15 are real and very well matched.
https://www.ebay.com/itm/323085516549
Stef.
EDIT: I bought some elsewhere on eBay and Ali in bulk and they were all fake. See pictures below. Specs was not good too.
These Fairchild FQA36P15 are real and very well matched.
https://www.ebay.com/itm/323085516549
Stef.
EDIT: I bought some elsewhere on eBay and Ali in bulk and they were all fake. See pictures below. Specs was not good too.
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I just trusted you ... and Jims_audio and I've ordered the 36P15! In the past, I bought 1 time from Jims with good result.
Thanks for the heads-up, finger crossed!
Nicola
Thanks for the heads-up, finger crossed!
Nicola
Assuming (1) a dual-mono arrangement, (2) the recommended PSUs build with the Saligny Standard synchronous bridges and (3) one PCB per stereo channel where the PSU and the amplifier are integrated (less connectors, less cables - if space allows, why not?): can the C12-D5-Q14-C14-R30 and the C18-C20 groups, as well as their negative rail counterparts be left out without compromising stability / sound quality, etc? Thanks, Miklos
Wow, that's quite the piece of hardware. I couldn't justify the spend, but there's a certain fascination (for me at least) in machine tools and it's so sweet when a tool makes a formerly difficult/time consuming job routine....
Where did you get the heatsinks?
Stef,
Could you please post the part number for the auto tapping tool, can't find much information about it on my side of the Pond.
Thanks
Could you please post the part number for the auto tapping tool, can't find much information about it on my side of the Pond.
Thanks
Bemato 56010?
https://www.maxodeals.com/mdenglish/jsn7-tap-holder-head-rth207-bem
I also tried Bemato RTH207.
Best,
Anand.
https://www.maxodeals.com/mdenglish/jsn7-tap-holder-head-rth207-bem
I also tried Bemato RTH207.
Best,
Anand.