Hi!
I was lucky enough to find a Bemato Rth-207 on sale cheap because parts were missing. The product is available under several brands. There are 3 models depending on the size of the taps.
Among the Chinese.
J467 M2-M7
https://fr.aliexpress.com/item/1005004415754939.html
https://fr.aliexpress.com/item/1005002960163038.html
Afterwards, you have to find the right connection according to your bench drill.
The tool is expensive. I hope I'll be happy with it and it will save me from breaking 15$ taps when I do tap by hand and as well spend much less time tapping.
I am waiting for him. I would tell you.
Stef.
I was lucky enough to find a Bemato Rth-207 on sale cheap because parts were missing. The product is available under several brands. There are 3 models depending on the size of the taps.
Among the Chinese.
J467 M2-M7
https://fr.aliexpress.com/item/1005004415754939.html
https://fr.aliexpress.com/item/1005002960163038.html
Afterwards, you have to find the right connection according to your bench drill.
The tool is expensive. I hope I'll be happy with it and it will save me from breaking 15$ taps when I do tap by hand and as well spend much less time tapping.
I am waiting for him. I would tell you.
Stef.
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Dear Tibi,
could you please quantify how much is the ripple reduced when using the Saligny Standard synchronous bridges compared to the standard diode bridge arrangement? I wonder, whether by including a Saligny-based PSU directly on the amplifier PCB one could ignore all the rail decoupling capacitors from 100nF to 2200uF and also Q13/14 together with their little "Christmas-trees" (so that the output stage rails are directly shared with the small-signal rails)? Would this be a good or bad idea in terms of stability and sound quality?
Another question: some drawings show rail fuses between the PSU and the amp. In contrast, the Saligny PSU has fuses before the rectifiers, in the AC line whereas your original amp design does not include further rail fuses on the amp board. What are the pros/cons/sonical impact of the two fuse arrangements?
Thank you,
Miklos
could you please quantify how much is the ripple reduced when using the Saligny Standard synchronous bridges compared to the standard diode bridge arrangement? I wonder, whether by including a Saligny-based PSU directly on the amplifier PCB one could ignore all the rail decoupling capacitors from 100nF to 2200uF and also Q13/14 together with their little "Christmas-trees" (so that the output stage rails are directly shared with the small-signal rails)? Would this be a good or bad idea in terms of stability and sound quality?
Another question: some drawings show rail fuses between the PSU and the amp. In contrast, the Saligny PSU has fuses before the rectifiers, in the AC line whereas your original amp design does not include further rail fuses on the amp board. What are the pros/cons/sonical impact of the two fuse arrangements?
Thank you,
Miklos
Hello Miklos,
Your questions indicate that you are not that well versed in the basics. MosFET based rectification has advantages in some points that Tibi has explained in different places, but these cannot replace smoothing capacitors. The current for the impulses when playing the amplifier is partly supplied by the capacitors, and so the sound characteristics do depend a lot on these components. For this reason, I have undertaken a series of experiments in order to achieve a very high quality of reproduction. Under these circumstances, the goal of minimising these elementary components is rather stupid.
Fuses are for the scared.... Not quite, but the fact is that if the fuses are installed before the filter capacitors behind the transformer, the amplifier can deliver cleaner bass beats than if the fuses are used between the filter capacitors and the power mosfet. According to the data sheets, the fuses in front of the power mosfets could be selected to be about 40A large, as these are supposed to withstand very high current peaks. However, the transformers can usually only deliver currents in the order of 8A at peak before they overheat.
Regards Tim
Your questions indicate that you are not that well versed in the basics. MosFET based rectification has advantages in some points that Tibi has explained in different places, but these cannot replace smoothing capacitors. The current for the impulses when playing the amplifier is partly supplied by the capacitors, and so the sound characteristics do depend a lot on these components. For this reason, I have undertaken a series of experiments in order to achieve a very high quality of reproduction. Under these circumstances, the goal of minimising these elementary components is rather stupid.
Fuses are for the scared.... Not quite, but the fact is that if the fuses are installed before the filter capacitors behind the transformer, the amplifier can deliver cleaner bass beats than if the fuses are used between the filter capacitors and the power mosfet. According to the data sheets, the fuses in front of the power mosfets could be selected to be about 40A large, as these are supposed to withstand very high current peaks. However, the transformers can usually only deliver currents in the order of 8A at peak before they overheat.
Regards Tim
I frequently read about problems getting the original FQA and FQP MosFETs. I have bought many of them because they are available in large quantities from the international wholesaler (RS Components International).
I also have a large number of the small MosFETs, but I use the ZVN4206A and ZVP2106A because the others broke down and their delivery also contained components with bad parameters. I can also offer these MosFETs here. Just send me a PM.
I also have a large number of the small MosFETs, but I use the ZVN4206A and ZVP2106A because the others broke down and their delivery also contained components with bad parameters. I can also offer these MosFETs here. Just send me a PM.
Dear Tim,
thank you for the reply. Please rest assured that I am not asking about leaving the 2x10000uF PSU filter capacitors after the synchronous rectifiers out. My concern is if the 2200uF rail decouplers right after the power input of the amp board are needed or not, IF the 10000uF caps are on board in a short distance from where they are the most needed, anyway.
As for the leaving the 100nF decouplers out, my question goes in the direction of how much spiking is left for additional removal after the synchronous rectifiers compared to a standard diode bridge case.
Third, in his original documentation, Tibi says that Q13/14 are not needed in case of synchronous rectification which obviously eliminates the gate protection Zeners as well. So the question is, if the remaining R29-C13 chain is needed or not. They look like a high-frequency filtering module which may or may not be necessary with the Saligny's.
I hope these clarify to you what I meant.
Best,
Miklos
thank you for the reply. Please rest assured that I am not asking about leaving the 2x10000uF PSU filter capacitors after the synchronous rectifiers out. My concern is if the 2200uF rail decouplers right after the power input of the amp board are needed or not, IF the 10000uF caps are on board in a short distance from where they are the most needed, anyway.
As for the leaving the 100nF decouplers out, my question goes in the direction of how much spiking is left for additional removal after the synchronous rectifiers compared to a standard diode bridge case.
Third, in his original documentation, Tibi says that Q13/14 are not needed in case of synchronous rectification which obviously eliminates the gate protection Zeners as well. So the question is, if the remaining R29-C13 chain is needed or not. They look like a high-frequency filtering module which may or may not be necessary with the Saligny's.
I hope these clarify to you what I meant.
Best,
Miklos
I have also cursed a lot when I had to drill threads. So I looked for an enclosure where I can reduce these tapped holes to 4 for the whole amplifier. The enclosure is not that very expensive for a full aluminium enclosure, and also available on Ebay England.
Here is a link to Aliexpress:
https://de.aliexpress.com/item/32965020902.html
Here is a link to Aliexpress:
https://de.aliexpress.com/item/32965020902.html
Hello Michlos,
I now understand better what you mean.
I deliberately use different capacitors in my setups so that I have ideal conditions for each frequency range and level range. I find the following to be favourable:
1. cup capacitors, at least 4.7 mF
2. high-quality electrolytic capacitors, like Panasonic EB-A with 470 uF
3. larger foils, here Wima MKP10 630V 680nF stands out as ideal. The MKP10 250V still sound too soft, the FKS sound indistinct, the MKS are unnecessary.
I have to add that I also reworked the transmission quality in the other areas of the amplifier, these are always just nuances, but in total it is a big difference to the original.
Regards Tim
I now understand better what you mean.
I deliberately use different capacitors in my setups so that I have ideal conditions for each frequency range and level range. I find the following to be favourable:
1. cup capacitors, at least 4.7 mF
2. high-quality electrolytic capacitors, like Panasonic EB-A with 470 uF
3. larger foils, here Wima MKP10 630V 680nF stands out as ideal. The MKP10 250V still sound too soft, the FKS sound indistinct, the MKS are unnecessary.
I have to add that I also reworked the transmission quality in the other areas of the amplifier, these are always just nuances, but in total it is a big difference to the original.
Regards Tim
Dear Tim,
special thanks for your Wima recommendations! ;-) While fully acknowledging your argument about using different caps to deal with the different frequency ranges of the noise spectrum, I would also like to add that electrolytic capacitors tend to inject measuable 1/f noise. So another approach/religion is to use as many of them as necessary but no more than that. I am trying to sit on that fence for now.
special thanks for your Wima recommendations! ;-) While fully acknowledging your argument about using different caps to deal with the different frequency ranges of the noise spectrum, I would also like to add that electrolytic capacitors tend to inject measuable 1/f noise. So another approach/religion is to use as many of them as necessary but no more than that. I am trying to sit on that fence for now.
My observation is that the Nichicon - Muse play very damped, which is very good as a mass coupling, the Panasonic EB-A sound very balanced with a somewhat soft melting, the Panasonic FR have a subtle tendency to already become too strict, with very good resolution, so rather what you describe, that their damping/internal resistance is too low or too unbalanced and can therefore favour these harmonics.
I have also cursed a lot when I had to drill threads. So I looked for an enclosure where I can reduce these tapped holes to 4 for the whole amplifier. The enclosure is not that very expensive for a full aluminium enclosure, and also available on Ebay England.
Here is a link to Aliexpress:
https://de.aliexpress.com/item/32965020902.html
Hi Tim,
I bought this one for the Q17-Turbo. The large knob at the middle will be replaced with a circular plate with the name of the amp.
https://de.aliexpress.com/item/1005005050289997.html
Stef.
I'm gathering up the parts for Q17 Amplifier and have not been able to source BS250P or ZVP2106A from the usual trusted component suppliers. Is there another alternative for Q9/Q11?
Thanks 🙂
Thanks 🙂
oh wait that's April 03 2024, wow, I have some on backorder that I hope will ship 03-Apr-23.
Mouser Part Number Customer Part Number Manufacturer Part Number Description | Quantity Remaining | Estimated Shipment Quantity | Estimated Shipment Date(s) |
20 | 20 | APR 03, 2023 | |
Production in Process |
Best alternative would be a 2 channel p-mos in same case.... Is there another alternative for Q9/Q11?
Thanks 🙂
https://eu.mouser.com/ProductDetail/onsemi-Fairchild/NDC7003P?qs=FOlmdCx%2BAA0uKvuS/nfMew==
Current mirror Q9-Q11 is critical part of Q17 amplifier and performance may be sensible improved if these are identical, on same silicon substrate.
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Hi!
Interesting this double transistor.
Could there be a true hole equivalent version?
It's easy to add this new SMD footprint on the back of the Turbo PCB.
Stef.
Interesting this double transistor.
Could there be a true hole equivalent version?
It's easy to add this new SMD footprint on the back of the Turbo PCB.
Stef.
OK, Thanks Tibi.
I would try the NDC7003P 'deadbug' style but the SSOT-6 package is just a bit too small to solder leads on. (3mm x 1.5mm)
Seems then VP2206 is best option.
I would try the NDC7003P 'deadbug' style but the SSOT-6 package is just a bit too small to solder leads on. (3mm x 1.5mm)
Seems then VP2206 is best option.
So wow I've decided, ....
I'm continuing my efforts and I'm going to finish completely the Q17 and fit it into the box. Each amplifier will be in a separate box - a monoblock!
I am currently working on a power supply, 8x MUR1560 +4x 22.000uF + 500 W toroidal transformer.

There is still a long way to go, ....
Then I will make a HICOCO version of softstart + ON/OFF and protection with relay.
I'm continuing my efforts and I'm going to finish completely the Q17 and fit it into the box. Each amplifier will be in a separate box - a monoblock!
I am currently working on a power supply, 8x MUR1560 +4x 22.000uF + 500 W toroidal transformer.

There is still a long way to go, ....
Then I will make a HICOCO version of softstart + ON/OFF and protection with relay.
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