If it were me, I would use the 1.0uF 50V ES at the input. Very wise move stocking up on those.
The 2.2uF version would work also, but is not necessary. In your situation, I would save the large caps for speakers.
For output caps, either good 10uF PP or else 10uF UES, to drive the 10k volume control.
For a proper answer you must show the load after those caps.
Until then, the question does not have a real answer.
Correct!
In what way does it not have an answer?
Shirley, the formula which gives the roll-off frequ is (approximately!): 160,000 / (uF * Rload).
So for the same Rload ... increasing the coupling cap will decrease the roll-off frequ.
With these old devices, the mass is often chased over the housing. I would check this and modify it if necessary.
The circuit board needs to be re-soldered. These solder joints are usually oversized and also with dubious solder. Do not solder the cables to the solder pins - remove them and connect the wires directly to the circuit board.
I would also try some electrolytic capacitors as coupling capacitors. The reason is the relationship between size and current definition, i.e. signal definition. Because the structure of capacitors also shows that current is not understood in its complexity;-) For example these:
https://na.industrial.panasonic.com...ytic-capacitors-radial-lead-type/series/83936
This is a very fine phono stage. You won't find many others with higher sonic potential.
The circuit board needs to be re-soldered. These solder joints are usually oversized and also with dubious solder. Do not solder the cables to the solder pins - remove them and connect the wires directly to the circuit board.
I would also try some electrolytic capacitors as coupling capacitors. The reason is the relationship between size and current definition, i.e. signal definition. Because the structure of capacitors also shows that current is not understood in its complexity;-) For example these:
https://na.industrial.panasonic.com...ytic-capacitors-radial-lead-type/series/83936
This is a very fine phono stage. You won't find many others with higher sonic potential.
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andyr said:
Shirley, we do NOT know the load, then your formula has no answer.
Anything multiplied by zero is zero.
By exactly the same reason anything multiplied by ???? is ????
Lowering the roll-off frequency does NOT mean increasing Bass, by any means.
If original cutoff frequency was 1 Hz, making it 0.1Hz will NOT give you "more Bass"
Shirley, we do NOT know the load, then your formula has no answer.
Anything multiplied by zero is zero.
By exactly the same reason anything multiplied by ???? is ????
Lowering the roll-off frequency does NOT mean increasing Bass, by any means.
If original cutoff frequency was 1 Hz, making it 0.1Hz will NOT give you "more Bass"
Anything you say, maaate - you are obviously a guru.
(But with the OP's system - with a coupling cap value of 0.47uF - working the formula says the roll-off frequ would be as follows, with various Zins of the following component:
- a Zin of 47k ==> a roll-off point of 7Hz
- a Zin of 33k ==> a roll-off point of 10Hz
- a Zin of 10k ==> a roll-off point of 34Hz.)
remember that turntables can have rumbles that are quite annoying, so the designer chose smaller output coupling caps...
After the signal exits the the phono preamp it makes its way to the selector switch and then switching for the tape monitors
Then makes its way over to the balance and volume pot where the loudness and muting controls are also. The balance being a 500 kohm pot and the volume 250 kohm for each channel.
From the volume it makes its way to the tone board.
Hopefully this gives a better idea of what the load is.
Dan
Then makes its way over to the balance and volume pot where the loudness and muting controls are also. The balance being a 500 kohm pot and the volume 250 kohm for each channel.
From the volume it makes its way to the tone board.
Hopefully this gives a better idea of what the load is.
Dan
The greatest sonic gains are not achieved by replacing capacitors but by completely re-soldering and removing many small unnecessary transitions, such as solder connections.
The capacitor values are correct, they can stay. Other capacitors make sense. But I would only choose them after reworking.
Other parts, as diodes, psu caps... then.
I would also completely omit the "preamplifiers". Completely unnecessary sound brakes.
I took a look at the power amplifier (service manual). But I only got a very blurred image. The power amplifier is not bad at all. It has R701/C701 and R702/C702 at its inputs. From the potentiometer just somewhere on it;-)
Phono > input selection > potentiometer > power amplifier. Just try it out. It will sound much cleaner in any case;-)
The capacitor values are correct, they can stay. Other capacitors make sense. But I would only choose them after reworking.
Other parts, as diodes, psu caps... then.
I would also completely omit the "preamplifiers". Completely unnecessary sound brakes.
I took a look at the power amplifier (service manual). But I only got a very blurred image. The power amplifier is not bad at all. It has R701/C701 and R702/C702 at its inputs. From the potentiometer just somewhere on it;-)
Phono > input selection > potentiometer > power amplifier. Just try it out. It will sound much cleaner in any case;-)
Alright, I’ll solder all of those posts as well as reflow all of the boards. I don’t wanna modify his piece of equipment too much by completely skipping over the control or removing a bunch of components. If it were my own, I’d be totally open to that, but I figured if I could get any sonic improvement by making some value changes then why not since I have them.
Another question I have is about the capacitors that the signal sees. I have read that ideally you want nonpolar capacitors where the signal goes through that capacitor, coupling capacitors. So for example, in this tone control circuit.
The input coupling capacitors are bipolar, but then the signal goes through CE05 and CE06 which are polar 4.7uF, CE19 and CE20 are polar 1 uF, CE21 and CE22 are polar 3.3 uF, then again at CE23 and CE24 they use bipolar 1 uF caps. If they have them for 23 and 24 why didn’t they use them at 19 and 20 as it’s the same value? Technically couldn’t all of these be bipolar if I wanted to replace them with bipolar is there a reason not to use bipolar in these positions?
They did use the good quality orange capacitors that are supposed to be low leakage that they generally use in the signal path of the amplifiers, just wondering if there’s any reason not to go bipolar. I could fill all of these positions with Nichicon UES.
Dan