Please select "phono" as the input when recording. This will stop the feedback.
sp16
with cables connected REC I select phono and makes me if I disconnect the oscillation is removed
phono only in the other entries
with cables connected REC I select phono and makes me if I disconnect the oscillation is removed
phono only in the other entries
Try the external op-amp based buffer I suggested in my last post. You can build one in an hour with a handful of parts, power for the experiment could be provided by a single 9V battery.
sp16
I see that in the circuit resistor R12 is 1M however has on three prior 10M in series and seen in real photographs and seen in internet
I see that in the circuit resistor R12 is 1M however has on three prior 10M in series and seen in real photographs and seen in internet
sp16
in the circle are the trs series resistors 10M
An externally hosted image should be here but it was not working when we last tested it.
in the circle are the trs series resistors 10M
Can't see it clearly but brown black black yellow brown is 1M ohm 1% precision resistor and that's what it looks like to me with my old eyes.
sp16 phono wrong
I've also noticed that when cleaning the needle on the run also makes me noise (push-push-push) for speakers which tells me that what is wrong is the phono
could help me
I've also noticed that when cleaning the needle on the run also makes me noise (push-push-push) for speakers which tells me that what is wrong is the phono
could help me
Of course cleaning the needle is going to cause the woofers to move, you shouldn't be doing that with the volume turned up. I'm more than a little concerned that you find this odd or an indication of a problem. The pre-amp probably has a gain of close to 80dB or so at 20Hz including the line stage gain so this should not come as a surprise.
Your tape recorder is not compatible with this pre-amp. I think you should discuss this with technical support at ARC.
I find it very doubtful that there is anything actually wrong with it beyond the fact that it was not designed to do what you expect, and your understanding of circuit design is too limited to figure things out.
Your tape recorder is not compatible with this pre-amp. I think you should discuss this with technical support at ARC.
I find it very doubtful that there is anything actually wrong with it beyond the fact that it was not designed to do what you expect, and your understanding of circuit design is too limited to figure things out.
sp16 phono wrong
I clean the needle with the volume and when I turn up the same noise that appears when I want to record it's like grids of the first valve are fed appears.
in audioresearch they tell me bring it to a technical service.
I clean the needle with the volume and when I turn up the same noise that appears when I want to record it's like grids of the first valve are fed appears.
in audioresearch they tell me bring it to a technical service.
phono sp16
hello there would be ways to modify the circuit by removing refeeding as it has
much gain and the input signal is overloaded
thanks
hello there would be ways to modify the circuit by removing refeeding as it has
much gain and the input signal is overloaded
thanks
This phono stage has 55dB midband gain, and is intended for low output cartridges. It can't be easily modified for less gain.
phono sp16
I just wipe the needle with the volume when the volume falls by
one backfiring on the speakers not saying it can be.
all shots are fine lands
salu2
I just wipe the needle with the volume when the volume falls by
one backfiring on the speakers not saying it can be.
all shots are fine lands
salu2
The sim show you can add a 100-200K volume pot to output to adjust the gain with no side effect.
He says the cartridge signal is too large for the 55dB gain, and is overloading the input,
so that a volume control at the output would not help.
I have a solution if decide against the 100k pot, you could install 12at7's disconnect the trim feedback, and install a 27k resistor between the cathodes of the gain stages. Below is the spiced schematic, good results and between 42 and 45dB gain. The PF resistor can be tailored for an even better response.
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phono sp16
I removed the three resistors in series of 10 M brings factory and I've put a 1M as in the scheme and now goes well (TRM!) on feedback
I removed the three resistors in series of 10 M brings factory and I've put a 1M as in the scheme and now goes well (TRM!) on feedback
I spiced the 1M resistor into the feedback, the AC sweep isn't very smooth, I'm not sure why ARC did this, I've spiced out several of their phono designs, and they aren't that great! at least their all tube designs! I'm not sure if their current designers use spice programs to test their new schemas or not, would be a helpful tool!
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With just 1M, the response is not straight (dip down 2.5dbs) after 150Hz or so. So I also change feedback resistor 137Kto 62K and cap 2276pf to 5nf in addition to TRM 1M, now appears smooth and gain down to -2 db.
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