Because dual mono with two bridges three wire center tapped transformer types won't work but this one has independent secondaries so its proper.
In any case give us a better description of the noise. Is it buzz or is it hiss? Covers the music itself or is it too high as a background?
In any case give us a better description of the noise. Is it buzz or is it hiss? Covers the music itself or is it too high as a background?
Secondaries are Black and red and Orange and yellow. Why is there a blue wire hooked up? Also, I would move the orange to the far left and the yellow to the next one.
The noise is like white noise (like resistor noise?), I'll try to record it .
The colors are not good because I've added some recuperated fuses between the transformer and the PSU.
The colors are not good because I've added some recuperated fuses between the transformer and the PSU.
A hiss kind of noise coming from the power section is not a fault ever reported before in this thread. Since the shunt regs adjust DC output in expected range and Vbe/Vgs check OK, things indicate that the semis there basically work. Unfortunately we can't nail the noise culprit with other simple tests. It takes a fully equipped bench analysis.
Semis come from Tea you said. That eliminates fakes questioning. In your shoes my next move would be to clean flux residue with isopropyl alcohol thoroughly top and bottom and try them again. If noise hasn't changed I would replace all semis in one shunt reg starting with MOSFETs. To compare noise between renewed and old shunt regulator channels. In case something compromised previous semis during assembly and test.
Semis come from Tea you said. That eliminates fakes questioning. In your shoes my next move would be to clean flux residue with isopropyl alcohol thoroughly top and bottom and try them again. If noise hasn't changed I would replace all semis in one shunt reg starting with MOSFETs. To compare noise between renewed and old shunt regulator channels. In case something compromised previous semis during assembly and test.
BTW after trying the things I suggested above and if the hiss reason will continue proving elusive to solve in your build, here's a band aid noise filter solution. But it will also eat a Volt or two. If the regs won't adjust high enough for that, increase their RVR1 to 3.3K.
Thank you all for your help.
I will be ordering the transistors for the replacement.
Can I replace the BD139 with ZTX 450 or 550 or 2SK170 that I have in stock?
I can listen to the vinyl with batteries in the meantime, it's not bad.
A strange question: Is it possible to add a volume pot between the last stages of the RIAA preamplifier?
I will be ordering the transistors for the replacement.
Can I replace the BD139 with ZTX 450 or 550 or 2SK170 that I have in stock?
I can listen to the vinyl with batteries in the meantime, it's not bad.
A strange question: Is it possible to add a volume pot between the last stages of the RIAA preamplifier?
Has to be NPN so the ZTX450 it is. Its hfe curve shows it can also pass a UFSP phono channel's current with some decent βeta. Only check it didn't get too hot. Because of its small size.
You can use a pot after final output not in between last stages. They are DC coupled and it would suffer there. What is the gain of your next stage?
You can use a pot after final output not in between last stages. They are DC coupled and it would suffer there. What is the gain of your next stage?
For the moment I don't have a preamp after the UFSP.
I don't need any gain.
I've tested direct to my treble amp and my active mid-bass crossover with the config "MC 56dB / S6 ON S10 ON all others OFF".
It's just a little too loud or ok depending on the record.
I'm thinking of doing a MEZMARIZE, but if I can avoid the preamp by adding a pot, I'd be interested.
(less is more).
medium and treble amps: 2107 SONY VFET
bass amp: KANEDA 209 DIY
active filter: modified LX MINI
(I'm too influenced by this forum...)
I don't need any gain.
I've tested direct to my treble amp and my active mid-bass crossover with the config "MC 56dB / S6 ON S10 ON all others OFF".
It's just a little too loud or ok depending on the record.
I'm thinking of doing a MEZMARIZE, but if I can avoid the preamp by adding a pot, I'd be interested.
(less is more).
medium and treble amps: 2107 SONY VFET
bass amp: KANEDA 209 DIY
active filter: modified LX MINI
(I'm too influenced by this forum...)
Using very sensitive horn speakers I guess. For 56dB phono mode on 0.3mV cart to seem loud without a line stage even. Unless the active crossover adds some gain. A 10k log pot has 2.5k worst case Zout so if your next stage has 25k input impedance or higher you should not have interfacing problems. Plus it will divide noise along dividing signal in that position.
Yes, compression driver with ALTEC 406 for midrange and 416 for bass.
Caps before the treble amp + active crossover with gain (for midrange + bass) + passive crossover (for midrange + treble).
It may not be the best or most optimized configuration, but I like to try differents things.
The main thing is that I like the sound of the system, especially with vinyl...
The preamp will see:
47k ohms in the SONY VFET 2017 (filter with caps before the amp).
25k ohms (pot) for the medium active filter
25k ohms (pot) for the active bass filter
So 9.9k ohms in total, it seems to me that this is not enough, if I replace the 25k pot by 50k, it's still 16k ohms.
I don't know if a 10k pot can work with 9.9k or 16k?
I think, I have no risk to try.
Caps before the treble amp + active crossover with gain (for midrange + bass) + passive crossover (for midrange + treble).
It may not be the best or most optimized configuration, but I like to try differents things.
The main thing is that I like the sound of the system, especially with vinyl...
The preamp will see:
47k ohms in the SONY VFET 2017 (filter with caps before the amp).
25k ohms (pot) for the medium active filter
25k ohms (pot) for the active bass filter
So 9.9k ohms in total, it seems to me that this is not enough, if I replace the 25k pot by 50k, it's still 16k ohms.
I don't know if a 10k pot can work with 9.9k or 16k?
I think, I have no risk to try.
Will struggle a bit wasting signal but you may give it a try. If it will sound too damped... Well, you tried.
Dear DIY friends,
First of all, I would like to thank Salas for his phenomenal project and his great help in making it.
Maybe because of laziness, I postponed the work for two years, but because of the Teac phonopreamp and its unnatural sound, I quickly decided to make it. My system consists of Kuzma S and 4point9, EMT HSD 006 phono cardtridge, Hifi Rose B150 preamp, Ncore amplifier and modified ML Request speakers. I just finished another pair of speakers that I will show you later on our DIY forum.
The Ultra operates at LOMC 62dB, 358 ohms and 220pF RIAA cap, it is completely silent on my 91dB sensitive speakers. I have yet to try Ultra in MM mode with good SUTs.
The sound is phenomenal. I'm in pure Nirvana ;-)
First of all, I would like to thank Salas for his phenomenal project and his great help in making it.
Maybe because of laziness, I postponed the work for two years, but because of the Teac phonopreamp and its unnatural sound, I quickly decided to make it. My system consists of Kuzma S and 4point9, EMT HSD 006 phono cardtridge, Hifi Rose B150 preamp, Ncore amplifier and modified ML Request speakers. I just finished another pair of speakers that I will show you later on our DIY forum.
The Ultra operates at LOMC 62dB, 358 ohms and 220pF RIAA cap, it is completely silent on my 91dB sensitive speakers. I have yet to try Ultra in MM mode with good SUTs.
The sound is phenomenal. I'm in pure Nirvana ;-)
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Very nice build congratulations! Happy to know that you like its sound so much.
Quite an eclectic system you got there by the way. What model is that Teac phono you did not like?
Quite an eclectic system you got there by the way. What model is that Teac phono you did not like?
Thank you Salas,
Teac PE 505. It sounded flat and artificial.
I chose it because of the control on the front panel and the excellent build (good power supply, solid case)
I'm still waiting for the top cover for the Ultra, which will be made of dark clear plexiglass to see the beauty inside. I decided on that because it is completely silent without a cover.
Teac PE 505. It sounded flat and artificial.
I chose it because of the control on the front panel and the excellent build (good power supply, solid case)
I'm still waiting for the top cover for the Ultra, which will be made of dark clear plexiglass to see the beauty inside. I decided on that because it is completely silent without a cover.
Attachments
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Hmm that's a 1600 Euro Teac phono. What your Pug dog says? I see listening calm to the electrostatics. Must be enjoying the UFSP too.🙂
That Teac seems to worth its price in build quality and internal parts indeed. Maybe it uses too many components though.
https://forums.stevehoffman.tv/threads/new-teac-pe-505-phono-preamp.919376/
https://forums.stevehoffman.tv/threads/new-teac-pe-505-phono-preamp.919376/
Huh
can do for 5000, 0 points from me, Ultra eats that for breakfast ;-)
Yes, it is technically very well made, but so is its sound, I confirmed it with a test with a Gold Note PH 10 preamplifier from a friend, which is again better than Teac.
can do for 5000, 0 points from me, Ultra eats that for breakfast ;-)
Yes, it is technically very well made, but so is its sound, I confirmed it with a test with a Gold Note PH 10 preamplifier from a friend, which is again better than Teac.
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