Nice chart. Useful I think, because easy to follow. I put its left part in the instructions post.
Values shown are bit rounded. 220//560//47000 will be 157.42 instead of 160 for instance.
The R1 47K resistor is always in circuit standing parallel. And there are parts tolerances too.
Rounded figures for cartridge loading are simple to look up and make no practical difference.
Values shown are bit rounded. 220//560//47000 will be 157.42 instead of 160 for instance.
The R1 47K resistor is always in circuit standing parallel. And there are parts tolerances too.
Rounded figures for cartridge loading are simple to look up and make no practical difference.
Hi yes I took some slight liberties in rounding to make a clean chart for my self Then after I finished I thought it would be useful for others.
Cheers
For what kind of cart you want this odd gain setting? In any case you should not allow more than 300-400mV phono output at 5cm/s velocity for a given cart + gain combination. Not to challenge the system's overload margin. In practical terms when you get increased ticks & pops and/or shouting transients with hints of distortion you know your gain is too much.
A cartridge with 2.12mV output, so at 472mV out could be pushing it. I want to try to use it with an Iron Pre with 6 db gain so going from 43 to the 47 should allow for overhead at my normal listening level but still allow for that pre, based on my current gain structure with a temporary setup. I get it might not work and am prepared to go back to a tube pre with plenty of gain. I just wasn't sure of the values to give it a go but wanted a chance for the iron pre to work and still have enough total gain available for the lower recorded records. Do you think 472 will be too easy to overload? If it is a non starter I can skip the iron pre. I just have a nice set of magnequest pinstripe chokes I wanted to use.
What is the Salas Shunt UBiB 1.3S board that I have seen used several times in this project? It does not look like the "Normal" UBiB 1.3 that I have built in the past. It appears to not contain reification. Is this being used in conjunction with the raw power supply boards as listed in the build manual?
It's a custom 1.3 UBiB made to supplement the phono. S stands for special. It does not have its own rectification and it only sets output in the voltage range that the phono uses. It also has provisions to drift the other way of what the phono input Jfets drift.
We keep the shunt reg next to the phono but the mains transformers and the rectification related board away in another box.
We keep the shunt reg next to the phono but the mains transformers and the rectification related board away in another box.
"21/6/19 The PF5102 JFET became EOL. But GB long term supply is secure. For substituting with J113 see info in post #1559"
Above info is from UBIB thread 33Vdc max. Can J113 sub PF5102 on UFSP? If no, any substitutes? Its the only part I'm don't have for the build. Thank
Above info is from UBIB thread 33Vdc max. Can J113 sub PF5102 on UFSP? If no, any substitutes? Its the only part I'm don't have for the build. Thank
It could work here too with proper value source pin resistors if 1.3S's J1 will not see >35V across it. Which is J113's VDS max spec. Asks not to exceed 43V RawDC input to this shunt reg. Approaching but not touching max spec this way. M1 Vgs and LEDs 1,2,3 Vf, drop the difference between those two voltages.
Is this board available? I do not see it listed on Teabag's latest group buy. Is it used in combination with the raw power board?
Its one thing with the UFSP board. There is a V score line in between circuits to can be broken away if it has to be positioned few cm apart or vertically in smaller phono boxes. Yes, its used in combination with the raw power board. Usually in different boxes connected with a umbilical cable. For avoiding hum interference in MC phono builds. Click to see UFSP Board Click to see RAW power board
You could try them for Q4,Q5,Q6 but with a 100 Ohm rheostat configured trimmer as R8. Adjusting it for 8V at Q4's drain. Q5 should be the one with smallest IDSS between them. But close. For the input stage there should be a 2SK369s quad as applied in MC stereo by everybody, no changes there.