@Craigl59 I can be as stubborn as anyone. Yeah, I tested the SMDs when I first soldered and installed them and they tested just fine....I told myself.
Well, with your prodding again I went back and added just a touch of solder to each of the gate legs of the 4 four JFETs to start and figure I would see where that would get me....and wouldn't you know....
SUCCESS!
Chassis resembled and I have incredibly sweet sounding music playing from the wonderful Pearl 3.
I appreciate the comment posts from everyone in an effort to push me along. I do appreciate it.
Well, with your prodding again I went back and added just a touch of solder to each of the gate legs of the 4 four JFETs to start and figure I would see where that would get me....and wouldn't you know....
SUCCESS!
Chassis resembled and I have incredibly sweet sounding music playing from the wonderful Pearl 3.
I appreciate the comment posts from everyone in an effort to push me along. I do appreciate it.
Sorry if I missed this but has anyone put together a BOM of the parts needs to complete the Modushop preamp/PSU chassis?
Thanks!
Thanks!
Cure for pain... How appropriate 😜Enjoying the Pearl 3 very much. Spinning contentment.
The newer vinyl releases I have bought recently sound amazing. There are still really great engineers that know how get the best out of this medium.
The RSD issue of 4 of the Ronstadt Asylum releases is superb -- very quiet and clean. With the P3 you do note the timbral superiority of original analog releases (prior to 1983 or so). Was fortunate to acquire a classical collection of 3k old records several years ago and the analog orchestral items are a powerful listening experience.
Currently I'm in the process of building the P3 into its enclosure. Finished wiring the back panel, so time for a test. Denon DL-110 cartridge, 49 dB gain, 47k load. I have the same problem as when I tested it before when it was not built in: a loud hiss in both channels (or should I say roar). Music does play. As soon as I switch a load resistor in parallell the hiss is gone and it is dead quiet and the music seems louder too. R34 is 1k2 in my case, sounds very good with that switched in. Default opamp is the OPA1612 at the moment, but hiss was there as well with the OPA1656, and with dual OPA 627 the P3 began to whistle (not from a record though ;-) ). Can it be that the P3 just does not like this cartridge? Next I will try it on another table with a LOMC cartridge and see if there it hisses too when I load it with 47k.
In theory, this is exactly what the zobel on dip switch #8 is intended to fix. Give it a try.
At the build manual
Please note that the LED in the transistor bag are precision voltage references, that happen to light up. Do not substitute any other color. Replace only with Lite-On LTL-1CHE.
Please note that the LED in the transistor bag are precision voltage references, that happen to light up. Do not substitute any other color. Replace only with Lite-On LTL-1CHE.
I've been a bad boy then 🙂. Mine works with the Vishay's. I did match them for Vf for both channels. In the datasheets, the If vs Vf curve seems quite similar for both types for currents between about 5 and 20 mA.
Other colors may have clearly different typical Vf, that's the reason for the warning in the build guide. Mouser even has red leds with 14V Vf, those would be clearly wrong in this position...
Other colors may have clearly different typical Vf, that's the reason for the warning in the build guide. Mouser even has red leds with 14V Vf, those would be clearly wrong in this position...
As long as you have Vf around 2 volt, everything is fine.
I bought 25pcs of LTL-1CHE, and all of them were between 1,7 to 1,8 volt. NONE were 2 volt.
Matched 2pcs 1,8 volts, and Pearl-3 plays like a charm😉
I bought 25pcs of LTL-1CHE, and all of them were between 1,7 to 1,8 volt. NONE were 2 volt.
Matched 2pcs 1,8 volts, and Pearl-3 plays like a charm😉