That is the 2nd time one of those has been built at my house and the 2nd time I’ve genuinely been sad when a component has left.
Beautiful faceplates by Patrick, very, very nice work overall, and of course the Salas Folded is absolutely incredible.
Had a wonderful time hosting, a fantastic weekend, thanks for coming out!!
Beautiful faceplates by Patrick, very, very nice work overall, and of course the Salas Folded is absolutely incredible.
Had a wonderful time hosting, a fantastic weekend, thanks for coming out!!
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Didn’t have time to get them installed.
Thanks!
It is set as MM. Plan is to roll some Cinemag SUTs in the back there by the switch. Waiting for them to arrive. All my current carts are MM/MI, but I want an audio education and options (MC)!
Currently 2 tables I built. “Beast” was a mass experiment, belt drive DC motor.. the low one I built first, Rega inspired with their AC motor and controller. Both have the opposite ends of the Grado woodbodies HO line. Also have an AT 540ML about. And picked up a Black Widow with an ADC XLM mkII improved for it to play with.
Next up is the SP-10 MKII pictured. Need to build a plinth.. Considering making it dual arm.
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Good stuff. Vgeorge has an SP10-MKII too and says to me it plays beautifully through the FSP. He uses a concrete plinth. On the lighter mass belt driven school front I was recently listening to a Bauer DPS3 with its own carbon unipivot and a Dynavector Te Kaitora Rua 0.26mV MC cart. Uses 3 Phase synchronous motor and a three wave generator PSU individually tuned to each motor sample. Another very good musicality result through the FSP.
Great info. I’ll look into all of it. 6L6 is sporting the SP-10MkIIA (hence my search for something from that era at his behest) and indeed it sounds exceptional (Too good? Haha!) and now I kinda have a reference of sorts when I plug it into my current setup..
Love to see some pics of the concrete plinth. I have had the exact same notion. Thank you very much for your design... and attentiveness to this thread! I am considering at least trying out a clear top (vented) for the amp.. see how it behaves hum-wise without a metal top.
I just got this together not long ago, so not a lot of critical listening, or even adjustment, and need to make sure it's all balanced out.
It's a Jelco 850-L tonearm. I wanted something to remove the headshell off easily, as I am clumsy and poor sighted and so I don't want to adjust carts too often.
It's a Jelco 850-L tonearm. I wanted something to remove the headshell off easily, as I am clumsy and poor sighted and so I don't want to adjust carts too often.
I just finished the PCB for my MM build. I power up the power supply and I have 52vdc on each channel output. I'm using a 50va 36v torroid transformer feeding the rectifiers. When I connected the power supply to the first channel PCB, three LED's light up like the instructions say, yet, the other four never light up. When I measure rail + to ground, I get 3vdc. I turned everything off, and went looking for any issues, no smoke, just low to no voltage at the rail.
Is the 52vdc to much from the power supply? It was measured unloaded.
Why is the rail + to ground voltage so low?
I'm not going to hook up the other channel PCB until I'm sure the power supply is good and I've fixed the cause of the rail + to ground voltage issue.
I'm scared to continue and damage the valuable JFET's.
Is the 52vdc to much from the power supply? It was measured unloaded.
Why is the rail + to ground voltage so low?
I'm not going to hook up the other channel PCB until I'm sure the power supply is good and I've fixed the cause of the rail + to ground voltage issue.
I'm scared to continue and damage the valuable JFET's.
Hi, when three LEDs are alight the PSU's constant current section around Q1x looks like working but the voltage section (shunt) shows a problem when reading 3V rail only. Are both Mosfets cold?
1. Inspect Q1x is IRF9610 and Q6x is IRF9530. Make sure all TO-92s in the PSU are what types they are supposed to be in the places they belong. R3x should have the expected value also.
2. Measure voltage drop across R1x to confirm the Q1x section works as a whole. Around 1.35-1.65V DC would be an expected range (90mA-110mA through 15Ω). If not, replace Q1x.
3. Measure Vgs between pins 1&3 both on Q1x and Q6x. Such type Mosfets at this current level give 3-4V Vgs readings when working. Q6x will possibly not. If so, replace it. If getting no good result yet, replace Q4x next. We will see about the JFETs later.
52V isn't a big problem right now. All it could do would be to break Q2x but in that case the three LEDs would be dark.
Its possible to be little lower when loaded. If there is expected drop across R1x measure Raw DC again. Now its loaded.
Put 33 Ohm 2W RD/Link position resistors instead of wire links in the Raw PSU at a point. So to drop a good chunk out of the 52V and avoid high dissipation on Q1x when the build will be ready.
Do the above for a start so we get a picture from the troubleshooting basics.
1. Inspect Q1x is IRF9610 and Q6x is IRF9530. Make sure all TO-92s in the PSU are what types they are supposed to be in the places they belong. R3x should have the expected value also.
2. Measure voltage drop across R1x to confirm the Q1x section works as a whole. Around 1.35-1.65V DC would be an expected range (90mA-110mA through 15Ω). If not, replace Q1x.
3. Measure Vgs between pins 1&3 both on Q1x and Q6x. Such type Mosfets at this current level give 3-4V Vgs readings when working. Q6x will possibly not. If so, replace it. If getting no good result yet, replace Q4x next. We will see about the JFETs later.
52V isn't a big problem right now. All it could do would be to break Q2x but in that case the three LEDs would be dark.
Its possible to be little lower when loaded. If there is expected drop across R1x measure Raw DC again. Now its loaded.
Put 33 Ohm 2W RD/Link position resistors instead of wire links in the Raw PSU at a point. So to drop a good chunk out of the 52V and avoid high dissipation on Q1x when the build will be ready.
Do the above for a start so we get a picture from the troubleshooting basics.
Hello Salas -I inspected the board and the IRF9610 is at Q1x, and IRF9530 is installed at Q6x.
I measured the voltage drop across R1x = 0v
Vgs between pin1 & 3 on Q1x = 6v
Vgs on Q6x = 0v
I checked the connections/solder joints from voltage in from PSU to R6x, all connections/solder joints are good, I'm using 33 ohms on R6x.
I measured the voltage drop across R1x = 0v
Vgs between pin1 & 3 on Q1x = 6v
Vgs on Q6x = 0v
I checked the connections/solder joints from voltage in from PSU to R6x, all connections/solder joints are good, I'm using 33 ohms on R6x.
I checked and double checked my work on the PCB and found an error on both channels.
I did NOT use an insulation pad behind the IRF9610 mounting to the heat sink.
I did use just thermal grease on the IRF9530, no insulation pad.
Both channels were built without the insulation pad and both channels act the same.
I'll add a pair of IRF9610's to my Mouser order.
Could this cause any other issues with the other parts?
I did NOT use an insulation pad behind the IRF9610 mounting to the heat sink.
I did use just thermal grease on the IRF9530, no insulation pad.
Both channels were built without the insulation pad and both channels act the same.
I'll add a pair of IRF9610's to my Mouser order.
Could this cause any other issues with the other parts?