BUT!!
now I see a problem with pcb itself - it's having all GNDs together, thus negating proper dual mono arrangement of BAL pcbs (channel GNDs isolated)
as I can't see traces on top side, I can't deduce is it enough just to make a cut from bottom side to isolate
it is, as is , absolutelly necessary to desolder pot ( carefully please) from pcb and to solder wires directly to pot pins
if needed, I'll make another sketch how to
now I see a problem with pcb itself - it's having all GNDs together, thus negating proper dual mono arrangement of BAL pcbs (channel GNDs isolated)
as I can't see traces on top side, I can't deduce is it enough just to make a cut from bottom side to isolate
it is, as is , absolutelly necessary to desolder pot ( carefully please) from pcb and to solder wires directly to pot pins
if needed, I'll make another sketch how to
Thanks for all the help ZM and IAIMH. The last redo did it. Everything's is working as it should. The Iron Pre is amazing!! So quiet, clean, transparent. I didn't think it would make as great a difference as it did. WOW. It brought the whole system up a notch.
Hi all, quick question, I'm building a SMD Balanced version, and I have bought the bundle pack.
In the SMD Balanced scematics, the value for R4,R5 is 18ohm. I only got 15ohm resistors left in the package. I assume this is close enough?
Same question for R35,R36,R37,R38. Scematic calls for 56ohm. I got 62ohm resistors in the package. Close enough?
Taking my time with this, as I really enjoy stuffing PCBs 🙂
In the SMD Balanced scematics, the value for R4,R5 is 18ohm. I only got 15ohm resistors left in the package. I assume this is close enough?
Same question for R35,R36,R37,R38. Scematic calls for 56ohm. I got 62ohm resistors in the package. Close enough?
Taking my time with this, as I really enjoy stuffing PCBs 🙂
^ Did you get a packing list in your kit? If not, apologies. There should be two lines in that list relevant to your question...
Resistors, Thermistors, and Potentiometers – If two values are noted, either will be fine
Resistors, Thermistors, and Potentiometers – If two values are noted, either will be fine
8 | R3, R4, R5, R6 | 15R or 18R |
^ Sorry about that... I typically count up enough to go in all of them and reconcile at the end. So, someone else go two... and you got zilch. 🙁
You'll probably wonder about these also, then. Thanks for understanding.
You'll probably wonder about these also, then. Thanks for understanding.
4 | R11, R12 | 2k67 or 2k74 |
8 | R35, R36, R37, R38 | 58R or 62R |
2 | R25 | 6k81 or 6k8 |
8 | R17, R18, R32, R34 | 825R or 820R |
4 | P1, P2 | 4k7 or 5k Pot |
pics, so I can see what you did
again, isolating channel GNDs is of substantial importance, when already made as dual mono
Transparent. Yes, that is a very accurate word for what I hear with this pre. Each time I build one, that is the result.
O...M...G.. So not boring if you make enough mistakes along the way, and then yes, yes, I suppose it is all just the same after that.
Good evening,
I have a quick question, I received the boards and was inspecting them. Just getting familiar with the layout. I noticed some extra solder and wanted to make sure this would not cause any issues? I have started stuffing the boards and had to go out of town. I am sure all is well, but had to ask.
Thank you, Kelly
I have a quick question, I received the boards and was inspecting them. Just getting familiar with the layout. I noticed some extra solder and wanted to make sure this would not cause any issues? I have started stuffing the boards and had to go out of town. I am sure all is well, but had to ask.
Thank you, Kelly
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Hi guys, I am trying to find Quasimodo results for Toroidy 30VA 2x18V audio grade transformers in order to populate the Quasimodo section of the Iron Pre Balanced SMD boards. While it's not necessary I am still thinking it would be a shame not to utilize the option since ZM so neatly has made it possible.
The closest I have found is in this thread: https://www.diyaudio.com/community/threads/quasimodo-equipment-question.376231/
In this thread the suggested Rx value for a 30VA 2x16V is 22-27ohm, standard CX and CS values. Is someone able to help me guesstimate suitable values for Rx, Cx and CS (not at all sure what would be standard CX and CS)?
The closest I have found is in this thread: https://www.diyaudio.com/community/threads/quasimodo-equipment-question.376231/
In this thread the suggested Rx value for a 30VA 2x16V is 22-27ohm, standard CX and CS values. Is someone able to help me guesstimate suitable values for Rx, Cx and CS (not at all sure what would be standard CX and CS)?
