This does not happen with the MyRef because the stereo source ground is connected to the signal ground, and the dual mono at most are connected to each other via power ground which is separated from the signal ground by a resistor; if you connect the dual mono in a Class II configuration, the power ground are left floating from each other. Perhaps you have traced incorrectly.
Why don't you address what I said is wrong instead of making hand waving blind statements like that.
USSR K71-4 Polystyrene Caps
My caps from Bucharest just arrived. Probably a dead subject, but....
Being a geek, the first thing I did was measure the body size. diameter is 22 mm and length is 48 mm.
I'm planning on following Bob's suggestion of soldering one end to the input connection (RCA to start) and the other to the board input. Is there any reason to use a jumper and keep the audio ground input close to the signal + input as they touch the board? I was thinking of just running the cap to the other end of the jumper/cap attachment on the board.
One question of curiosity. The caps are listed as 1 uF in English. They are marked as 1 MK(Greek letter Phi). Did they use another measure of capacitance in the USSR?
I love this kind of stuff. I look forward to a few cap comparisons when the FE's getting working.
My caps from Bucharest just arrived. Probably a dead subject, but....
Being a geek, the first thing I did was measure the body size. diameter is 22 mm and length is 48 mm.
I'm planning on following Bob's suggestion of soldering one end to the input connection (RCA to start) and the other to the board input. Is there any reason to use a jumper and keep the audio ground input close to the signal + input as they touch the board? I was thinking of just running the cap to the other end of the jumper/cap attachment on the board.
One question of curiosity. The caps are listed as 1 uF in English. They are marked as 1 MK(Greek letter Phi). Did they use another measure of capacitance in the USSR?
I love this kind of stuff. I look forward to a few cap comparisons when the FE's getting working.
Hi Jac,
No, simply if you use the jumper you can mount the connector to the other end of the input cap, allowing an easy detach from board.
If you plan to not use the Molex connector you can solder to the pad without problems.
My K71 caps arrived today too. The first thing I did was check the capacitance(with my cool new amprobe AM-270
DMM) I ordered two pairs. The first set measured at 1.005uf and 1.006uf. The second set was. 995uf and. 996uf. A great match. I don't know if it was intentional or just luck but so far I am happy. I can't wait to try some other caps for comparison.
DMM) I ordered two pairs. The first set measured at 1.005uf and 1.006uf. The second set was. 995uf and. 996uf. A great match. I don't know if it was intentional or just luck but so far I am happy. I can't wait to try some other caps for comparison.because in post947, you quoted the whole post and did not highlight or identify what you took exception to.
If you disagree with any one or many particular statements/phrases then be specific and we can have a useful exchange.
I have stated, in what I consider to be clear english, what needs to be done to identify the problem. You are doing the hand waving by generallising and getting distracted by introducing the HOT side of the Signal Route. I keep referring you back to the Return side of the signal route but you ignore that direction.
Last edited:
I think the 1 refers to capacitance
The M refers to metalised
The K refers to film
The last letter if shown usually refers to the type of film.
Sorry, in no post have I ever referred to the hot side. If I have, why don't you quote it out and highlight it?
It has been clear that the RCA ground is connected to the signal ground on one channel, which is separated from the signal ground in the right channel via R11 in each channel. This breaks the ground loop you mention. Please check again and address the exact ground loop path you are talking about. Additionally, if people just leave the power ground (GND in the schematic) open in the MyRef, then the ground loop is not even an issue in a dual mono configuration.
Last edited:
Connect a stereo Source to a stereo amplifier.
That input has a Ground Loop.
That loop does not exist if one connects a stereo Source to a pair of Monoblocks.
That loop does exist if one connects a stereo Source to a Dual Mono Amplifier.
Look at the ground side ONLY to see the problem
That input has a Ground Loop.
That loop does not exist if one connects a stereo Source to a pair of Monoblocks.
That loop does exist if one connects a stereo Source to a Dual Mono Amplifier.
this is coupling of the Signal, that is the Hot side.
Look at the ground side ONLY to see the problem
1 MK(Greek letter Phi) = 1uF
That letter looking like a greek Phi is infact F in russian alphabet so you have 1mkf. Russians write everything like they hear.
Greetings from Bucharest
K71-4 warning
All people that bought K71-4s, when plannning how to mount them, should take in account they're polystyrene film/foil caps.
Pystyrene caps are very sensitive to heat and, usually, can be soldered only one time.
If you must desolder them for whatever reason the caps will be probably damaged.
Probably the best way to mount them is directly on PCB using both C13 pads, even if they're longer than the True Copper.
It can be implemented on any My_Ref.
All people that bought K71-4s, when plannning how to mount them, should take in account they're polystyrene film/foil caps.
Pystyrene caps are very sensitive to heat and, usually, can be soldered only one time.
If you must desolder them for whatever reason the caps will be probably damaged.
Probably the best way to mount them is directly on PCB using both C13 pads, even if they're longer than the True Copper.
It can be implemented on any My_Ref.
Last edited:
Polystyrene capacitor leads will benefit from using a heatsoak clip just like semiconductor leads love these tools.
Instead I turn up my soldering temperature from the usual 300ºC to 320ºC, clean the tip on the damp sponge and aim for a very fast soldering time with small diameter 63/37.
Instead I turn up my soldering temperature from the usual 300ºC to 320ºC, clean the tip on the damp sponge and aim for a very fast soldering time with small diameter 63/37.
Last edited:
Sorry, but you are talking about a different amplifier, not the MyRef.
Additionally, common power ground between two channels of power amplifiers also effect cross talk. If you don't agree, it's fine with me, I have no intent to convince you.
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.