Back in the early 80s we used to run RS232 terminals at a much longer distance (hundreds of meters) than supposedly was possible. We used good quality shielded cable and attached the shield to chassis ground at one end of the cable only, thus avoiding loops.
Using that same method (for single ended use) you would use the 2 insulated wires in standard microphone/balanced cable for signal and gnd and would connect the shield at one side only to chassis gnd. After my recent experiences with radiated noise in a test setup of a preamp, I will be trying this method myself. YMMV
This it it twisted shielded wires I assume?Using that same method (for single ended use) you would use the 2 insulated wires in standard microphone/balanced cable for signal and gnd and would connect the shield at one side only to chassis gnd. After my recent experiences with radiated noise in a test setup of a preamp, I will be trying this method myself. YMMV
Yes, it should be very good. The shield protect against RF and the twisting against magnetic induced noise in the cable.
I think this is how most HighEnd RCA cables are made but you could make the same much cheaper.
I have been lazy and I need some very good RCA connectors anyway (twist lock preferred). So I say......100 USD is ok for at cable if connectors are top quality.
But interesting to "DIY".......
About cables:
https://ing.dk/holdning/audiohomoeopater-og-kabeltosser
The Danish guy "Poul-Henning Kamp" is "burdened by concrete knowledge" and the thread is quite fun to read and his arguments.......but you need to learn Danish or use google translate
Yes, we used twisted pair for those terminals in those days.
Ideally I would use twisted pairs, but I recently saw and bought 5 meters of cheap 30AWG UL2547 shielded (but not twisted) cable at Aliexpress for testing. At under US$4 for 5m I could not resist to try it out for that preamp I am testing
Ideally I would use twisted pairs, but I recently saw and bought 5 meters of cheap 30AWG UL2547 shielded (but not twisted) cable at Aliexpress for testing. At under US$4 for 5m I could not resist to try it out for that preamp I am testing
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Why 36 and not 2x18?
TTSA0030 - Transformer AUDIO TSA30VA - voltage to 50VOutput voltage: 36 V; Mounting pad: Filled epoxy resin #07
This looks ok.
Gae.
It would be quite easy to parallel as one set of JFETs can be soldered at the backside of PCB.
Do you think the 2SK/2SJ octets sold by DiyStore are close enough for paralleling?
Then I would need a "double" octet for a BAL pre.
I am only allowed to buy one octet pr. month
I would be good to get 2 x octets that are relative close.......for symmetry reasons.
Do you think the 2SK/2SJ octets sold by DiyStore are close enough for paralleling?
Then I would need a "double" octet for a BAL pre.
I am only allowed to buy one octet pr. month
I would be good to get 2 x octets that are relative close.......for symmetry reasons.
Yes, I meant mW....
So you think there is physical space enough on PCB on front side to parallel......even if 2SK170 / 2SJ74 are used......
I wonder if DiyStore 2SK/2SJ octets are 0.1 mA matched......I don't think they specify it.
Next is to be able to buy two octets that are close to each other.
So you think there is physical space enough on PCB on front side to parallel......even if 2SK170 / 2SJ74 are used......
I wonder if DiyStore 2SK/2SJ octets are 0.1 mA matched......I don't think they specify it.
Next is to be able to buy two octets that are close to each other.