I bought the full UFSP kit through TeaBag’s Reverb store and I am just about ready to get started on my build. Having read through almost this entire thread, the GB thread and the available build guides for the UFSP and the FSP (pause to catch breath), I believe I have a solid understanding of this design and construction methodology used to implement it. A huge THANK YOU to Salas and TeaBag for this project and your incredible support of our DIY community.
As for parts, I ordered ClarityCap CMR series for C3/C4. I see a lot of builders here used the various Mundorf high-end variety caps in the C3 position, and that copper caps are referenced here and there, so I might experiment later on with those. Z-Foil resistors in the R1 and Rx cartridge loading slots are also popular, and I am a fan of Z-Foils, so I am debating their use here. The high precision resistors included in the kit are no slouches though, so I wonder if anyone has done an A-B comparison between the two, and if the Z-Foils make a noticeable improvement? Also, aside from R1 and Rx, would Z-Foils add anything to the party if used for R4 and R17?
I am really glad to have been able to get in on the fun here so late in the game, and am looking forward to hearing my UFSP upon completion!
-Glen
As for parts, I ordered ClarityCap CMR series for C3/C4. I see a lot of builders here used the various Mundorf high-end variety caps in the C3 position, and that copper caps are referenced here and there, so I might experiment later on with those. Z-Foil resistors in the R1 and Rx cartridge loading slots are also popular, and I am a fan of Z-Foils, so I am debating their use here. The high precision resistors included in the kit are no slouches though, so I wonder if anyone has done an A-B comparison between the two, and if the Z-Foils make a noticeable improvement? Also, aside from R1 and Rx, would Z-Foils add anything to the party if used for R4 and R17?
I am really glad to have been able to get in on the fun here so late in the game, and am looking forward to hearing my UFSP upon completion!
-Glen
You are welcome. And good luck with your build.
In my experience the chiefly influential resistor to secure best quality for is R17.
In my experience the chiefly influential resistor to secure best quality for is R17.
Hi Salas - Appreciate your response. I guess then I will try a Z-Foil in R17 and will leave all others as supplied.
Maybe a layout problem? I don't know this board. Else replace the reg's 560 BJTs first. Then M1.
I follow you layout and made this one.I double check the layout and do not find layout issue.I Have replaced M1.but issue still there.let me replace the 560 BJT
Can someone check my math I'm trying to do the front panel LED and I want to make sure it's as straight forward as I think
(V-Vled)/I=r. 34-2.4/0.01=3.16k ohms
After thought.... What range would be acceptable?
(V-Vled)/I=r. 34-2.4/0.01=3.16k ohms
After thought.... What range would be acceptable?
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Math is OK. Usually 10mA gives strong light for a panel Led. Distracting especially in a darkened room. 1mA is more likely a target. Or even less. Also have a 33K resistor in hand to compare.
Funny not funny story. I gave my friend a pair of 2.7 uF Mundorf caps to try on the output of USFP.
He changed the caps, sent some recorded music and we tried to figure out if there was a diffrence to previous Russian Teflons.
Turns out he swapped interstage caps.
Still, I'd be very curious to hear some feedback from some members interested in hearing A/B.
So the C3 change was from paralled Teflon FT-2s to Mundorf Supremes. Different values from before and after (paralleled 0.047uF to 2.7uF)
Recorded A/B tracks are here presented:
https://we.tl/t-CGLgoZEAkZ
At the beginning, I couldn't hear the difference. First, blind A/B listening test on headphones and DCG3 showed random and low confidence score.
Although two later comparison series on different days gave 94% and 96% confidence out of 15 trials.
Out of curiosity, I'd like to know if others are hearing the difference. If yes, what's their preference.
Nick, I assume we have increased impedance with that 2.7uF value?
He changed the caps, sent some recorded music and we tried to figure out if there was a diffrence to previous Russian Teflons.
Turns out he swapped interstage caps.
Still, I'd be very curious to hear some feedback from some members interested in hearing A/B.
So the C3 change was from paralled Teflon FT-2s to Mundorf Supremes. Different values from before and after (paralleled 0.047uF to 2.7uF)
Recorded A/B tracks are here presented:
https://we.tl/t-CGLgoZEAkZ
At the beginning, I couldn't hear the difference. First, blind A/B listening test on headphones and DCG3 showed random and low confidence score.
Although two later comparison series on different days gave 94% and 96% confidence out of 15 trials.
Out of curiosity, I'd like to know if others are hearing the difference. If yes, what's their preference.
Nick, I assume we have increased impedance with that 2.7uF value?
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With such high value interstage cap the effect is there is no roll off under 20Hz anymore. Wasn't steep but designed to help with rumble and loudspeakers feedback to the turntable. When on headphones the latter is irrelevant. Rumble remains.
Hello and thanks Salas,
so the recommended value would be 100uF and of similar brand (eg. Mundorf Supreme) or doesn't really matter as there's already a Mundorf in C4?
The recordings were made with only low level speaker feedback. So it might not be that pronounced. I hear very little difference and I can't detect rumble on the presented passages via headphones. But it's interesting to see that an A/B leans to say there is difference and if so, I have a slight preference for 2.7 uF Mundorf.
Depends on the speaker and turntable. If with soft surround reflex loaded woofer and a sensitive turntable on not very inert rack, excessive cone movement may happen in frequencies below port resonance. Especially if there is eccentricity in some records.