Just saw this post 😱
A 10k Dact and wires to input and output RCA's No more/no less
Dead Simple and Surprisingly effective on Both a CDP and a phono stage input.
As in I've not heard better.
YMMV of course, but impressed the heck out of me, it also continues to do so.
I have it working. Pretty big offset for about 8 seconds then it settles down but it wanders slightly. The preamp has an input cap so shouldn't be an issue. I have only played a sine wave through it so far but that looks good. I need to rig up a volume pot so I can test it through the preamp. I will report back when I have that done. Here's a pic of the Tube MM, its PSU and the Counterpoint.
Blessings, Terry
Blessings, Terry
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You have full rail voltage on cold tube anode, with heating tube start conducting and voltage on anode drop... phono mm preamp have RIAA EQ so gain will change with frequency, maximum gain is at low and minimum at high, you can change sine wave frequency and test EQ... nice work.
Regards
Hi Mile,
I tested it along with the Counterpoint. It is just as you say. The output goes down as the frequency goes up. I never knew that. Always fun to learn something new. The transformer I'm using has 4 primary windings. 120VAC, 100VAC and two 6.3VAC. I'm using the 120VAC for the Counterpoint and the 100VAC for the Tube MM. One 6.3VAC feeds the counterpoint heater and mute circuit and the other feeds the Tube MM. I am feeding the heater circuits with 6.3VAC and using 100n caps to ground from each leg. I got the idea from Valery's hybrids and it works well. I need to clear some room to set up my turntable so I can test the sound. Looks good on the scope.
Blessings, Terry
I tested it along with the Counterpoint. It is just as you say. The output goes down as the frequency goes up. I never knew that. Always fun to learn something new. The transformer I'm using has 4 primary windings. 120VAC, 100VAC and two 6.3VAC. I'm using the 120VAC for the Counterpoint and the 100VAC for the Tube MM. One 6.3VAC feeds the counterpoint heater and mute circuit and the other feeds the Tube MM. I am feeding the heater circuits with 6.3VAC and using 100n caps to ground from each leg. I got the idea from Valery's hybrids and it works well. I need to clear some room to set up my turntable so I can test the sound. Looks good on the scope.
Blessings, Terry
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I got a chance to test it today. I woun't work as I have it in the picture above. There is a pretty loud hum. Maybe I have the volume control wired incorrectly, I'm not sure.
I did get both circuits to work independently. They each work OK. The Counterpoint has a lot of gain. but sounds pretty good. I tested the phono stage against the one in my Yamaha preamp and the Yamaha sounds noticeably better. The Tube MM is a bit muffled. Of course that may change with a different tube, I don't know. One other thing that may affect the outcome is that I didn't have any 27K 1W resistors so I used 33k. I will order some 27K and change that out and have another listen.
Blessings, Terry
I did get both circuits to work independently. They each work OK. The Counterpoint has a lot of gain. but sounds pretty good. I tested the phono stage against the one in my Yamaha preamp and the Yamaha sounds noticeably better. The Tube MM is a bit muffled. Of course that may change with a different tube, I don't know. One other thing that may affect the outcome is that I didn't have any 27K 1W resistors so I used 33k. I will order some 27K and change that out and have another listen.
Blessings, Terry
OK so I have a question. I have this transformer. I want to power both boards with the same transformer. I tried using the 120V winding for the Counterpoint and the 100V winding for the Tube MM. They each work stand alone but once I connect them together there is a strong hum. I suspect it has to do with the fact that the transformer is center tapped. Can you take a look at the circuits and see if it is possible to make this work?
Thanks, Terry
Thanks, Terry
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