vinyl-62 Posted December 28, 2024 Posted December 28, 2024 I was wondering if I could get some advice with regards to Goldenage MM/MC phono stage that I have recently acquired. I don't seem to getting enough gain out of the phono stage. I have tried it with both MM cartridges and MC using his accompanying SUT. Should I look at replacing the rectifier tube before I seek advice from a technician. Using an MM cartridge the preamp volume is at around 3 o'clock before it starts to become acceptable. With previous phonostages the volume on the preamp would be at around 11 o'clock. Would anyone recommend a repairer in Sydney that could look at this unit. Any advice would be greatly appreciated!
andyr Posted December 28, 2024 Posted December 28, 2024 38 minutes ago, vinyl-62 said: I was wondering if I could get some advice with regards to Goldenage MM/MC phono stage that I have recently acquired. I don't seem to getting enough gain out of the phono stage. I have tried it with both MM cartridges and MC using his accompanying SUT. Should I look at replacing the rectifier tube before I seek advice from a technician. Using an MM cartridge the preamp volume is at around 3 o'clock before it starts to become acceptable. With previous phonostages the volume on the preamp would be at around 11 o'clock. Would anyone recommend a repairer in Sydney that could look at this unit. Any advice would be greatly appreciated! It would've helped you to get some useful answers if you had told us what MM & MC carts you had used. The default/standard gain for an MM phono stage ... is 40dB = 100x gain. This is because the default/standard output of an MM cart is 5mV - so 500mV comes out of the phono stage. I seem to remember the gain of Duc's phono stage is a bit less than 40dB; if it is 38dB ... you will get only 395mV out ... which will mean you'll have to turn up your preamp volume control. And if your MM cart puts out less than 5mV ... this will compound your problem.
vinyl-62 Posted December 28, 2024 Posted December 28, 2024 Thanks for your response. The MM is an AT VM740ML Cartridge and the MC is an AT ART1000 cartridge. The MM phono stage built into Earle's preamp has plenty of gain for the MM cartridge.
andyr Posted December 29, 2024 Posted December 29, 2024 (edited) 19 minutes ago, vinyl-62 said: Thanks for your response. The MM is an AT VM740ML Cartridge and the MC is an AT ART1000 cartridge. The MM phono stage built into Earle's preamp has plenty of gain for the MM cartridge. Aah, OK. The specs of your AT VM740ML say it is 4mV output - not 5mV! So you have a lower-than-normal-output MM combined with a low-gain MM phono stage. Hence you need to turn up the preamp volume control. Re. your AT ART1000 MC cart, the specs say it has a low output (0.2mV). You haven't said what coil ratio DUC's SUT is (1:10? 1:20?) but even if it's 1:20 ... you will still have only 4mV going into the MM phono stage. And re. Earle's preamp's phono stage having "plenty of gain for the MM cartridge" - he presumably has built in a higher-than-40dB phono stage. (I can build the MM version of my Muse phono stage with up to 47dB gain (224x) - which makes it very useful for HOMCs which have 1.5mV output.) Edited December 29, 2024 by andyr
vinyl-62 Posted December 29, 2024 Posted December 29, 2024 (edited) 20 minutes ago, andyr said: Aah, OK. The specs of your AT VM740ML say it is 4mV output - not 5mV! So you have a lower-than-normal-output MM combined with a low-gain MM phono stage. Hence you need to turn up the preamp volume control. Re. your AT ART1000 MC cart, the specs say it has a low output (0.2mV). You haven't said what coil ratio DUC's SUT is (1:10? 1:20?) but even if it's 1:20 ... you will still have only 4mV going into the MM phono stage. And re. Earle's preamp's phono stage having "plenty of gain for the MM cartridge" - he presumably has built in a higher-than-40dB phono stage, (I can build the MM version of my Muse phono stage with up to 47dB gain (224x) - which makes it very useful for HOMCs which have 1.5mV output.) I'm confused with regards to the 1:16 - 1:32. Edited December 29, 2024 by vinyl-62
andyr Posted December 29, 2024 Posted December 29, 2024 1 minute ago, vinyl-62 said: I'm confused with regards to the 1:16 - 1:30. Aah, OK - thanks for the pic. So Duc's SUT has two windings: 1:16 - which increases the cart signal by 16x and 1:32 - which increases it by 32x. For an MC with 0.2mV output ... you would use the 1:32 option ==> 6.4mV into DUC's phono stage. I would've thought that should produce a loud enough signal from his phono stage for you not to have to turn up your preamp volume control excessively? OTOH, if you've been using the 1:16 tap ... then you're only putting 3.2mV into Duc's MM phono stage (less than the 4mV from your MM cart). So, yes, the preamp volume control will have to be turned up more than when your MM cart is in use.
RockRolley Posted December 29, 2024 Author Posted December 29, 2024 13 minutes ago, andyr said: And re. Earle's preamp's phono stage having "plenty of gain for the MM cartridge" - he presumably has built in a higher-than-40dB phono stage. Despite building tube amps, last I heard from Earle, he uses a pre-built solid state phono stage in his amps. Doesn’t do his own RIAA circuits 1
vinyl-62 Posted December 29, 2024 Posted December 29, 2024 1 minute ago, RockRolley said: Despite building tube amps, last I heard from Earle, he uses a pre-built solid state phono stage in his amps. Doesn’t do his own RIAA circuits That is correct. He uses a module from Canada. 1
SonicArt Posted December 29, 2024 Posted December 29, 2024 Pretty sure I have used the 1194, here is the PDF for it. You may need to rewire something unless DUC has made it easy to change from serial to parallel to the transformer windings. LUNDHAL LL1943.pdf 1
vinyl-62 Posted December 29, 2024 Posted December 29, 2024 (edited) 1 hour ago, SonicArt said: Pretty sure I have used the 1194, here is the PDF for it. You may need to rewire something unless DUC has made it easy to change from serial to parallel to the transformer windings. LUNDHAL LL1943.pdf 30.72 kB · 2 downloads Thanks Mark I'll take it to a local guy and see if he can rewire the SUT. Edited December 29, 2024 by vinyl-62
Vinylear Posted December 29, 2024 Posted December 29, 2024 Just a thought, is one of the valves failing?
vinyl-62 Posted December 29, 2024 Posted December 29, 2024 16 minutes ago, Vinylear said: Just a thought, is one of the valves failing? That was my initial thought also and went hunting in the attic for a rectifier tube-5AR4 that I thought I had but could not find it. I'm not sure if you can use other rectifier tubes in this unit.
Vinylear Posted December 29, 2024 Posted December 29, 2024 It could be one of the other valves. Sorry I don't know what they are called. Gain valve?
andyr Posted December 29, 2024 Posted December 29, 2024 46 minutes ago, vinyl-62 said: Thanks Mark I'll take it to a local guy and see if he can rewire the SUT. How did Duc connect up the SUTs? Do you have 2 possible sets of terminals: one using the 1:16 circuit and one for the 1:32 circuit? Or did he wire it with just one pair of terminals - so he's already made the gain choice for you?
vinyl-62 Posted December 29, 2024 Posted December 29, 2024 3 minutes ago, andyr said: How did Duc connect up the SUTs? Do you have 2 possible sets of terminals: one using the 1:16 circuit and one for the 1:32 circuit? Or did he wire it with just one pair of terminals - so he's already made the gain choice for you? He wired this with only one choice of terminals, so I suspect it's 1:16.
andyr Posted December 29, 2024 Posted December 29, 2024 1 minute ago, vinyl-62 said: He wired this with only one choice of terminals, so I suspect it's 1:16. Aah, OK. If you only have one set of terminals, I would agree that he probably wired it for 1:16. BTW, you can confirm this because 16x gain applied to your 0.2mV MC cart would mean 3.2mV going into Duc's phono stage - so MC will sound quieter than your MM, with the preamp volume control unchanged (given your MM is 4mV). (If SUT/MC actually is louder ... then he wired it as 1:32.)
vinyl-62 Posted December 30, 2024 Posted December 30, 2024 On 29/12/2024 at 2:26 PM, andyr said: Aah, OK. If you only have one set of terminals, I would agree that he probably wired it for 1:16. BTW, you can confirm this because 16x gain applied to your 0.2mV MC cart would mean 3.2mV going into Duc's phono stage - so MC will sound quieter than your MM, with the preamp volume control unchanged (given your MM is 4mV). (If SUT/MC actually is louder ... then he wired it as 1:32.) I have managed a couple of comparisons across the MM mounted turntable and the MC mounted turntable without changing the volume. It seems as though the volume is louder on the MC mounted turntable. Very strange! I will move forward with replacing the tubes to see if that rectifies the problem, if this does not work then to a technician it goes! It certainly does not have enough gain for my system.
andyr Posted December 30, 2024 Posted December 30, 2024 2 minutes ago, vinyl-62 said: It certainly does not have enough gain for my system. Aah, that's a shame - as it is a beautiful-sounding MM phono stage. Now, you said: 10 minutes ago, vinyl-62 said: It seems as though the volume is louder on the MC mounted turntable. Then it would seem Duc must've wired the SUTs in their 1:32 mode (so 6.4mV is going into the phono stage, with your ART1000 - compared to 4mV with your AT VM740ML)? If it's still not at the loudness level you like ... you might like to consider using an active gain stage with your AT ART1000 (instead of the SUT) - having a higher gain than 32x? I can supply one of my 'Paris' head amps with the gain set to, say, 40x. This would also allow you to choose the loading you thought sounded best (instead of the loading delivered by the SUT - which would be 46 ohms, if the SUT is wired for 1:32). Please PM me if you're interested in learning more.
RockRolley Posted December 30, 2024 Author Posted December 30, 2024 I don’t currently have my Goldenage mm/mc phone stage connected but I don’t recall any volume issues. I’ll hook it up ASAP and advise if I notice anything unusual
RockRolley Posted December 30, 2024 Author Posted December 30, 2024 (edited) 3 minutes ago, andyr said: I can supply one of my 'Paris' head amps with the gain set to, say, 40x. This would also allow you to choose the loading you thought sounded best (instead of the loading delivered by the SUT - which would be 46 ohms, if the SUT is wired for 1:32). Please PM me if you're interested in learning more. Goldenage plus Andy’s Paris head amp is a dream combo. I have both Edited December 30, 2024 by RockRolley Typo 1
andyr Posted December 30, 2024 Posted December 30, 2024 Just now, RockRolley said: Goldenage plus Andy’s "patriots" (Paris) head amp is a dream combo. I have both Thanks, Simon. 1
vinyl-62 Posted December 30, 2024 Posted December 30, 2024 7 minutes ago, andyr said: Aah, that's a shame - as it is a beautiful-sounding MM phono stage. Now, you said: Then it would seem Duc must've wired the SUTs in their 1:32 mode (so 6.4mV is going into the phono stage, with your ART1000 - compared to 4mV with your AT VM740ML)? If it's still not at the loudness level you like ... you might like to consider using an active gain stage with your AT ART1000 (instead of the SUT) - having a higher gain than 32x? I can supply one of my 'Paris' head amps with the gain set to, say, 40x. This would also allow you to choose the loading you thought sounded best (instead of the loading delivered by the SUT - which would be 46 ohms, if the SUT is wired for 1:32). Please PM me if you're interested in learning more. I think something like the Paris Headamp could be a great way to move forward but the lack of volume is also on the MM side. So I will check the tubes first and if that does not deal with the issue I will then get the unit checked to make sure that everything as it should be. This is a beautifully built phonostage with an amazing parts list. 1
RockRolley Posted December 30, 2024 Author Posted December 30, 2024 18 minutes ago, vinyl-62 said: I think something like the Paris Headamp could be a great way to move forward but the lack of volume is also on the MM side. So I will check the tubes first and if that does not deal with the issue I will then get the unit checked to make sure that everything as it should be. This is a beautifully built phonostage with an amazing parts list. I know of somebody with a Goldenage phono stage who had a few mods done (not by Duc) which reduced the volume-along with whatever the mood was supposed to achieve. Is yours stock?
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