Sorry, guys, 2nd question ... this time re. the 4.7uF coupling cap.
Your circuit has it coming off the 1st stage Drain - before the RIAA.
I have seen another, similar, circuit where it is after the RIAA, feeding the Gate of the second stage (and the 1Meg shunt to ground).
What is the effect of having it in each position?
Thanks,
Andy
Your circuit has it coming off the 1st stage Drain - before the RIAA.
I have seen another, similar, circuit where it is after the RIAA, feeding the Gate of the second stage (and the 1Meg shunt to ground).
What is the effect of having it in each position?
Thanks,
Andy
Thanks, Salas.
Yes, much better to use a higher-quality, smaller cap ... without having to pay as much for it as you would with a big cap!
Regards,
Andy
PCB Build
OK, here is my build, sounds great. No hum with the shielding on the transformer.
OK, here is my build, sounds great. No hum with the shielding on the transformer.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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Congratulations! And thanks for the feedback. You are the first to report a GB PCB build and I am happy nothing went wrong. Was it all clear with the guide? Tell us a bit about the system it plays in if you like.
*I attach your pictures here because they did not show up directly in your post.
*I attach your pictures here because they did not show up directly in your post.
Attachments
Not sure why I'm having problems with the photos today.
Anyway, here is a photo of the system. 845PP transformer coupled amps driving my horns with W subs on the bottom end.
The Guide was great! Big improvement over commissioning the point to point version. I did have to tweak R3x to get the reg in the correct range, per your guide.
Anyway, here is a photo of the system. 845PP transformer coupled amps driving my horns with W subs on the bottom end.
An externally hosted image should be here but it was not working when we last tested it.
The Guide was great! Big improvement over commissioning the point to point version. I did have to tweak R3x to get the reg in the correct range, per your guide.
Hey, hey, an expert's DIY system nonetheless.
What is the cartridge and what gain did you choose to build for? Impressive that you got no hum nuisance with a toroid Tx in the phono box on horn speakers, even when you shielded it.
About the pictures, it seems that the host does not relay, but I downloaded your system's picture and I attach it as well. Better use attachments in the future. You can also know how it will appear by hitting preview before submit.
What is the cartridge and what gain did you choose to build for? Impressive that you got no hum nuisance with a toroid Tx in the phono box on horn speakers, even when you shielded it.
About the pictures, it seems that the host does not relay, but I downloaded your system's picture and I attach it as well. Better use attachments in the future. You can also know how it will appear by hitting preview before submit.
Attachments
Hey, hey, an expert's DIY system nonetheless.
What is the cartridge and what gain did you choose to build for? Impressive that you got no hum nuisance with a toroid Tx in the phono box on horn speakers, even when you shielded it.
About the pictures, it seems that the host does not relay, but I downloaded your system's picture and I attach it as well. Better use attachments in the future. You can also know how it will appear by hitting preview before submit.
Ortofon Kontrapunkt B, 56dB gain, single K369.
Thanks,
I had listened to that cart briefly in the recent past in a tubes system and i found it good almost up there with some Lyras. A nice choice, and the gain choice is wise for it too.
Did you keep the RIAA treble caps C2+C2Y at the 15.2nF averagely recommended value or you had to tweak?
I'm at 15.15nF currently, I will most likely add the 50pf at some time. It does not sound bright to me now. My biggest observation is that the low level detail is much improved over the point to point version with separate regulators. Definitely a step up.
vs the point to point folded. This circuit is much better than the original non folded version. My buddy had his pearl over here last weekend and the point to point version of the folded was much more spacious, the PCB version is in another league.
Many thanks,
Very good news. I strived to provide a standard so for all to have the same dense enough general layout with no cables to regs too and a predictable ground for the most part between builds. The parameters that in P2P vary between builders in other words. I am glad it worked out. Enjoy, and thanks again for your feedback. 
transformer choice
Can anyone advise?
I am planning to build the Folded PCB, I already have all the parts, but have a doubt about the transformers. In fact I already have one Nuvotem toroidal of 2x18V / 15VA, and was thinking of buying another one for the other channel.
Is this power enhough (one transformer per channel)?
Thanks.
Can anyone advise?
I am planning to build the Folded PCB, I already have all the parts, but have a doubt about the transformers. In fact I already have one Nuvotem toroidal of 2x18V / 15VA, and was thinking of buying another one for the other channel.
Is this power enhough (one transformer per channel)?
Thanks.
Ok thanks, but in that case I will buy a new 80VA unit (to be used by both channels) and will only spend 8€ more when compared to buying another 15VA and take the risk of over-heating. Although we can think of better performance with 2 transformers, I will anyhow use two bridges and separate filters.
Yes, 2 bridges and separate filters are preferable but, surely, if you want "the ultimate" PS, you should use a separate bridge & filters for each gain stage? So 4 in all - with, I suggest, 2 transformers (so, 1 for each channel).
Regards,
Andy