I am used to cover them with heatshrink and it does work very well indeed.
Maybe this is the better way to do it
I did not try it because I was afraid the superglue would impact the trannies plastic casing.
Heatshrink is tricky because it needs heat to be installed and I already "cooked" some 369 this way.
If it is a very important to keep these two 369s in constant and very-very tight temperature range, then there is only one way to do it - to use water active cooler system. It is a bit mess since need to move it out to separate box and to use flexible tubes in order to isolate vibration coming from its pump. Nothing better is working and this is how our body do regulate temperature with 36.6 Deg C precisely.
Off course we must use distilled, purified water.
It is not even Di-ionized (DI) water. it is DI mix with some pure glycol.
However, I think is it utopia to use such complex cooling if it is not so needed there.
I'll say no. Not needed. A long time (+6 months) 10 degree Celsius shift haven't disturbed my enjoinment
. But then again, my ears has maybe had time to adapt Regards
I though Mr. Kosha was being sarcastic! Still do, actually.
I am a bit confused - I did not think the difficulty in getting the 369's to settle down was due a difference in temperature between them but their temperature in general. Not that I doubt some kind of coupling could be useful.
Some kind of isolation does make sense and it should not be too difficult to implement.
I am wondering if the coolers could be used to make a little tent. I would hesitate to glue the two devices together but wonder if some form of attachment for the cooler either glue or an alligator clip and then cover this with something that is not a good conductor taken down to the PCB land that would allow enough atmosphere for a constant temperature. Maybe lead sheet/foil?
Going to look for some lead foil if such a thing exists.
something like this: http://www.amazon.com/Sheet-Lead-1-...UTF8&qid=1407171495&sr=8-3&keywords=lead+foil
I am a bit confused - I did not think the difficulty in getting the 369's to settle down was due a difference in temperature between them but their temperature in general. Not that I doubt some kind of coupling could be useful.
Some kind of isolation does make sense and it should not be too difficult to implement.
I am wondering if the coolers could be used to make a little tent. I would hesitate to glue the two devices together but wonder if some form of attachment for the cooler either glue or an alligator clip and then cover this with something that is not a good conductor taken down to the PCB land that would allow enough atmosphere for a constant temperature. Maybe lead sheet/foil?
Going to look for some lead foil if such a thing exists.
something like this: http://www.amazon.com/Sheet-Lead-1-...UTF8&qid=1407171495&sr=8-3&keywords=lead+foil
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Nah, did everybody forgot bimetals? They bend by themselves due to temp. I will pursue this track myself when time given. A small box with holes at he bottom of the walls and a roof automatically opening as temp rises. When it cools down it closes... There is no need of speed in this application.
Regards
That is clever but I think you, too, are having some fun!
Ordered the lead sheet so I will be able to try it out. Hoping to have my power supply (#2) finished by this weekend. This time I am substituting the SALAS shunt with a BELLESON series reg with a bleeder on the output to mimic a shunt but with the advantage of true voltage regulation which I hope might make it easier to get the 369s to their bias. Brian is a friend and I have used his regs in many projects. I had so much trouble with my first go at the phono amp so I thought I might better my odds with not having to assemble the regulator.
The BELLESON is installed at the RAIL point - about 2 mm from board to board. The ground line has to be a little longer. Traces connecting to the shunt reg have been cut. Power goes straight to the reg in and ground straight to ground.
Hope my apostasy will be forgiven - but we all know apostasy can never be forgiven. Just no pronouncements of anathema, please ...
Going with choke input since I had a pair of old DYNACO power amp power transformers (50 volts no load my AC line) and a bunch of giant chokes (500 mA, 5H, 26 R) that I have had for decades.
This supply will be far away from the phono amp. Using lengths of wire from SOLEN hepta litz 14 ga loudspeaker coils. Really nice wire - good for lower frequency loudspeakers, not subwoofers, though.
I know my sonic impressions will be useless since I have made such a fundamental change but I have a feeling most of the goodness will be there and I bet my bass response is a little better.
With time (and boredom/need for a change) I will install the shunts and hear what happens.
Ordered the lead sheet so I will be able to try it out. Hoping to have my power supply (#2) finished by this weekend. This time I am substituting the SALAS shunt with a BELLESON series reg with a bleeder on the output to mimic a shunt but with the advantage of true voltage regulation which I hope might make it easier to get the 369s to their bias. Brian is a friend and I have used his regs in many projects. I had so much trouble with my first go at the phono amp so I thought I might better my odds with not having to assemble the regulator.
The BELLESON is installed at the RAIL point - about 2 mm from board to board. The ground line has to be a little longer. Traces connecting to the shunt reg have been cut. Power goes straight to the reg in and ground straight to ground.
Hope my apostasy will be forgiven - but we all know apostasy can never be forgiven. Just no pronouncements of anathema, please ...
Going with choke input since I had a pair of old DYNACO power amp power transformers (50 volts no load my AC line) and a bunch of giant chokes (500 mA, 5H, 26 R) that I have had for decades.
This supply will be far away from the phono amp. Using lengths of wire from SOLEN hepta litz 14 ga loudspeaker coils. Really nice wire - good for lower frequency loudspeakers, not subwoofers, though.
I know my sonic impressions will be useless since I have made such a fundamental change but I have a feeling most of the goodness will be there and I bet my bass response is a little better.
With time (and boredom/need for a change) I will install the shunts and hear what happens.
The integrated shunts do regulate their voltage output vs their internal Norton Vref too. The 369s drift due to temperature delta, not due to varying voltage. If you will scope the rail when using the on-board shunt regs you will also see the tell tale steady straight line as expected by a stable reg in general.
I'm sorry since I didn't mean to create such big blast for "creative" ideas all around 369s biasing. I was not sarcastic at all and still believe that the most practical method to create precisely stable, means almost constant, temperature set-point is to use active cooling. Same practice of cooling used for combustion engines or CPU/RAM/Flash/Blades/HDs so on. Noting new in that technique.
In our case, as Salas mentioned, it is not needed to be that precise. In addition, I got the same scenarios as RCruz expressed, and when is top-lid is closed, the bias is much more stable. At that point it was easy for me to set it to 3.6V +/- 0.05V.
Done deal and it sounds amazing...
In our case, as Salas mentioned, it is not needed to be that precise. In addition, I got the same scenarios as RCruz expressed, and when is top-lid is closed, the bias is much more stable. At that point it was easy for me to set it to 3.6V +/- 0.05V.
Done deal and it sounds amazing...
your "water" needs chemicals to ensure you don't breed a health hazard.Off course we must use distilled, purified water.
Of course, Mr. Kosha is correct that liquid cooling is the best way to insure a fairly constant temperature.
I thought he was being humourous because I cannot imagine how to implement it without a cooling system that is bigger than the phono amp.
If this can be done on such a small scale I would love to give it a try.
The liquid jacket would have to be in intimate proximity to the 369s and there is not much room and then the tubing and the pumps and noise from the pumps - but then we could remote mount those ...
YIKES!
I thought he was being humourous because I cannot imagine how to implement it without a cooling system that is bigger than the phono amp.
If this can be done on such a small scale I would love to give it a try.
The liquid jacket would have to be in intimate proximity to the 369s and there is not much room and then the tubing and the pumps and noise from the pumps - but then we could remote mount those ...
YIKES!
