Will these jumpers be suitable?
https://uk.farnell.com/amphenol-icc...-jumper-0-1-gold/dp/1097974?st=header jumpers
https://uk.farnell.com/amphenol-icc...-jumper-0-1-gold/dp/1097974?st=header jumpers
Go for these:
40 Pins PCB Connectors Straight Angled Header Single Row Solder Strip Jumper | eBay
£1.38 for 10 and they are perfect. Black to match the PCB.
Just got my trafo today from DIYERZONE. Opened the box and got a nice whiff of what smells like epoxy or even acetone. Must be some glue. I figure I'll be a guinea pig and try el cheapo especial. It cost me $40 shipped to the US.
Cool.
Quite often I'm left wondering what the smell is, when I open a package from China.
Just remember to check the voltages are correct
I got the same transformer and it works fine. The voltages are a touch high but everything is regulated on this PCB so not a big deal. There are a few gotchas though!
1. The low voltage secondaries MUST be paralleled with the coils in phase. I used a dim bulb tester and when they are wired out of phase, the bulb is bright and no voltage present. When in phase, the bulb is not lit and ~11.3VAC is present. I HIGHLY recommend the dim bulb tester to avoid damaging the transformer!
2. The low voltage regulator on the PCB is a full-wave rectifier which needs a center-tap secondary. These are NOT center-tapped, so you need to add 2 more 1N4002 diodes to create a virtual ground as show in the image below.
Everything is up and running and it sounds great! More details on testing later but thought I'd post this for those planning to use the Chinese R-Core transformer.
1. The low voltage secondaries MUST be paralleled with the coils in phase. I used a dim bulb tester and when they are wired out of phase, the bulb is bright and no voltage present. When in phase, the bulb is not lit and ~11.3VAC is present. I HIGHLY recommend the dim bulb tester to avoid damaging the transformer!
2. The low voltage regulator on the PCB is a full-wave rectifier which needs a center-tap secondary. These are NOT center-tapped, so you need to add 2 more 1N4002 diodes to create a virtual ground as show in the image below.
Everything is up and running and it sounds great! More details on testing later but thought I'd post this for those planning to use the Chinese R-Core transformer.
Attachments
craigtone, I’m curious why you can’t just connect the secondaries in series and use the connection between the two as a center tap? Additionally, if you created a virtual ground between the paralleled 9v secondary, wouldn’t that make -4.5, 0, 4.5v rails?
I just want to make sure I understand correctly since I have a -9.5, 0, 9.5v secondary on order.
Thanks!
Greg
You could put them in series but that is too much voltage drop and would generate a lot of heat in the regulator. Also, each secondary is only rated at 1A, so putting them in parallel gives me 9V@2A. The virtual ground is independent of the transformer winding, so it does not affect the 9VAC output.
I recently bought a pcb from a member in Indonesia. The tracking info showed that it was due to leave Indonesia for over a week. Went for a walk one day and came home to find it on the doormat. I don't know whether tracking info with stuff from China is the same.
These guys are usually pretty good but it seems Covid-19 has slowed things down, understandably.
I'll continue to check and when an update is available, I'll share it.
Pretty sure I got this all entered right...but is that what your ordered? I still dont trust myself ordering this stuff..
Profile : Standard
Total Power : 35.00VA
Frequency : 60Hz
Primaires:
1 x 0 - 115 V
Secondaires:
2 x 0 - 9.5 V / 1 A (9.50 VA)
1 x 0 - 165 V / .1 A (16.50 VA)
+ Electrostatic Screen
+ Magnetic Screen
Steady7, this is what I ordered:
The main difference is that I ordered it with a 19v center tapped secondary (which I think is correct).
To do this on Audiophonics site, under the "Secondary circuit" option, set a 9.5v/1A secondary, click "Edit", click "Enable" under "Mid Point". I've attached a screenshot of what this looks like.
Again, I'm just going off of the 9.5-0-9.5 / 1A specs recommended in https://www.diyaudio.com/forums/gro...brid-valve-phonostage-pcb-18.html#post6103967, I would love confirmation from Bigman80 or others familiar with the circuit.
Greg
The main difference is that I ordered it with a 19v center tapped secondary (which I think is correct).
To do this on Audiophonics site, under the "Secondary circuit" option, set a 9.5v/1A secondary, click "Edit", click "Enable" under "Mid Point". I've attached a screenshot of what this looks like.
Again, I'm just going off of the 9.5-0-9.5 / 1A specs recommended in https://www.diyaudio.com/forums/gro...brid-valve-phonostage-pcb-18.html#post6103967, I would love confirmation from Bigman80 or others familiar with the circuit.
Greg
