Attachments
I had the wisdom to buy lots of the R100's, so there will be continued
product either of J2's or something else.
The issue about two channel supplies and grounding is largely economic.
Better isolation is afforded by mono chassis, and for stereo units the
grounding layout becomes more critical. I use the "hierarchical" approach
and the result as noted by Stereophile is an isolation on the order of -100 dB.
I weigh that against the approximately double cost of mono.
Mono is not for everyone since if you aren't going all of the way with it it is almost nonsense.
No question it would probably not be much cheaper than just getting two J2s.
Now we will all be studying to figure out how to implement a hierarchical ground!
Take care,
Any thoughts on whether the J2 would adequately drive a pair of B&W 705? Measurements of these speakers by Stereophile can be found here. For the record, I live in an apartment and listen rather quietly. Have had great success with tube amps (300b, 6C33C) and a mini-Aleph, but less success with Forte 1a and First Watt F5 clone. The latter two amps yield sound which is somewhat bright and bass-shy.
Finally got around to replacing the stock power supply in my original J2 after living with the mono J2 I made with the Thai case using one of the channels of the original.
Had to try choke input just to hear what might happen. I do not ever remember hearing of a choke input supply amp that sounds bad.
Using a 30 volts (x2) ANTEK transformer and the same LUNDAHL chokes leading to a 33mF cap and then the .117R resistor ending up with the 100mF cap before entering the circuit. The other channel is simply 18 volts (x2) into the 33mF cap - LUNDAHL choke - 100mF cap into the circuit.
My AC line is a little high. I am seeing +- 26 volts loaded. I had thought those monster rectifiers I am using had a higher Vf than they do. I guess I should have used a 28 x 2 transformer to get it the same as stock. Again, the extra 2 volts might be a benefit?
After listening for a couple of hours I am sure this is the way to go. Further listening did nothing to dissuade me.
There is an ease, and even greater ease than with the CLC filter in the other channel. I wonder, too, if the little extra voltage might have a good effect?
Now to order another transformer and consider this project finished.
What I am hearing makes me wonder if I should replace the transformer in the SIT1 and add the same choke and just insert this voltage into the stock power supply board.
I had been cautioned not to fool around with the power supply of the SIT1 due to the need for a governed start up. I noticed with the choke input J2 that at start up the voltage comes up much slower than the CLC one. I think this could be a safe modification if the space can be found.
Not seeking a blessing on this but I would appreciate being cautioned, again.
Had to try choke input just to hear what might happen. I do not ever remember hearing of a choke input supply amp that sounds bad.
Using a 30 volts (x2) ANTEK transformer and the same LUNDAHL chokes leading to a 33mF cap and then the .117R resistor ending up with the 100mF cap before entering the circuit. The other channel is simply 18 volts (x2) into the 33mF cap - LUNDAHL choke - 100mF cap into the circuit.
My AC line is a little high. I am seeing +- 26 volts loaded. I had thought those monster rectifiers I am using had a higher Vf than they do. I guess I should have used a 28 x 2 transformer to get it the same as stock. Again, the extra 2 volts might be a benefit?
After listening for a couple of hours I am sure this is the way to go. Further listening did nothing to dissuade me.
There is an ease, and even greater ease than with the CLC filter in the other channel. I wonder, too, if the little extra voltage might have a good effect?
Now to order another transformer and consider this project finished.
What I am hearing makes me wonder if I should replace the transformer in the SIT1 and add the same choke and just insert this voltage into the stock power supply board.
I had been cautioned not to fool around with the power supply of the SIT1 due to the need for a governed start up. I noticed with the choke input J2 that at start up the voltage comes up much slower than the CLC one. I think this could be a safe modification if the space can be found.
Not seeking a blessing on this but I would appreciate being cautioned, again.
- just go for itI must have misunderstood your instructions!
Many times my assumptions get in the way of my understanding.
From what I am hearing there is something about having that nice sinusoidal waveform feeding the circuit instead of what you get with every other filtering scheme. The squiggles may be very small (the AC remaining) but they still infect the transposed output of the amplifier.
Right now my imagination is running wild with the presumed improvement brought upon the SIT1s with a choke input supply. Of course, the improvement will not be anywhere near what I am imagining which is why this phase of a modification is the best. Just like wanting some new toy. The acquisition rarely satisfies for anywhere near as long as the longing.
If we realized, at this point, how small the improvement is actually going to be we would not bother. But, in the end, there is the cumulative effect of all of our enthusiastic modding which does result in a worthwhile improvement.
AS ALWAYS my appreciation for the one who makes all of this possible with his unobtanium devices, unrelenting circuit explorations along with being personable, gregarious and interactive and to the indispensable man of Pass inspired extrapolations, ZEN MOD, for counsel and encouragement.
Can't wait for the ZM Diamond Buffer and the new regulator.
Happy New Year
Many times my assumptions get in the way of my understanding.
From what I am hearing there is something about having that nice sinusoidal waveform feeding the circuit instead of what you get with every other filtering scheme. The squiggles may be very small (the AC remaining) but they still infect the transposed output of the amplifier.
Right now my imagination is running wild with the presumed improvement brought upon the SIT1s with a choke input supply. Of course, the improvement will not be anywhere near what I am imagining which is why this phase of a modification is the best. Just like wanting some new toy. The acquisition rarely satisfies for anywhere near as long as the longing.
If we realized, at this point, how small the improvement is actually going to be we would not bother. But, in the end, there is the cumulative effect of all of our enthusiastic modding which does result in a worthwhile improvement.
AS ALWAYS my appreciation for the one who makes all of this possible with his unobtanium devices, unrelenting circuit explorations along with being personable, gregarious and interactive and to the indispensable man of Pass inspired extrapolations, ZEN MOD, for counsel and encouragement.
Can't wait for the ZM Diamond Buffer and the new regulator.
Happy New Year
That's about the best news I've had all month and Stereophile's most intelligent decision in recent memory! Congratulations Papa!