PSU1 to power 24v Rega Turntable
Printed From: Graham Slee Hifi System Components
Category: And the rest
Forum Name: Power Sources
Forum Description: Where the power comes from has always been a hot topic - even more so now with new World legislation
URL: https://www.hifisystemcomponents.com/forum/forum_posts.asp?TID=2629
Printed Date: 27 Mar 2026 at 12:35am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: PSU1 to power 24v Rega Turntable
Posted By: Drewan77
Subject: PSU1 to power 24v Rega Turntable
Date Posted: 23 Jul 2015 at 7:35pm
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Is there a possibility to adapt a GSP PSU1 to supply 24v to a Rega TT-PSU in place of the Rega wall-wort? I have been considering a power supply from elsewhere but it occurred to me that this may be suitable & I would rather purchase from GSP if it was feasible  ------------- Older than I once was, younger than I'll be ............................. Andrew |
Replies:
Posted By: Fatmangolf
Date Posted: 23 Jul 2015 at 9:52pm
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Alas not, the TT supplies 24 Volts AC to power the Rega's motor. The 24V DC from a PSU1 is incompatible. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Graham Slee
Date Posted: 23 Jul 2015 at 10:34pm
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Not so fast Jon! I registered an AC version when I got the CB certificate back in 2003 (or was it 2004?) However, it might not be exactly 24 V AC. I have to test that out, and transformers (what the AC comes out of) have a thing called transformer regulation, which means the voltage is higher no-load than it is loaded. I also have to check what the certificate said about the output current. Although it can do 12 AC Watts it was tested to the worst possible outcome, which limits what we can declare. Quite odd I thought: some Chinese power supplies supposedly carrying the same approval and transformer rating are allowed to declare much higher output current. (so honesty is the best policy?...) ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: Drewan77
Date Posted: 24 Jul 2015 at 7:06am
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Thank you Graham, that sounds positive. Please let me know as soon as possible as I was about to order an alternative ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 24 Jul 2015 at 7:58am
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Sorry to disagree but the TT PSU isn't just an AC to AC transformer. That model of the PSU1 has an AC output available from the internal transformer and it may well be slightly better than the equivalent AC to AC transformer Rega supply, but it is not going to match what the TT PSU does. The Rega TT SU is DC powered with an oscillator producing a clean 50Hz sine wave for 33 1/3 rpm and 67.5 Hz for 45 rpm which boosted to drive the turntable's motor. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 24 Jul 2015 at 8:50am
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Does this need some clarification? This is what I am asking about - a replacement for the wall-wort that supplies 24v to the Rega TT-PSU:  It plugs into the rear of the TT-PSU using one of these:  ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Graham Slee
Date Posted: 24 Jul 2015 at 9:16am
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The label says it has a 50Hz input which is the mains frequency common to all UK mains supplies (and is 50Hz in many other countries using 220-250 volts) It doesn't state the output frequency, but if it is just a transformer inside then its output will still be 50Hz. The voltage is stated as 24. It has a squiggle after it that means it is AC (alternating current - just like the mains is). If it were a different frequency safety rules say the frequency should be stated. It also shows the current rating which is 350mA, and that should be taken as meaning the maximum safe current that can be "drawn". To me it looks just like any other OEM plug-top transformer badged up at no extra cost if you order sufficient. I once did the same and my guess is it is made by the same Chinese company. If my memory serves me well the on-load voltage of the PSU1 transformer is 23 volts. The output current we are allowed to rate the product at whilst conforming to IEC60950 is 200mA but it is capable of much more. Since going from regular fuse protection to an internal transformer winding resetable fuse, the output current can be much more, but to be able to rate it higher we would have to put it through compliance testing again, but don't have the spare £10K to do it. Most manufacturers choose the easy route of buying in a certified power supply - even those who could afford to get their own through the certification process. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: JamesD
Date Posted: 24 Jul 2015 at 12:28pm
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More to the point, is changing the Rega psu to another type going to make any improvement? If so, how, and what would the psu provide to achieve this? ------------- Aren't ears brilliant |
Posted By: Richardl60
Date Posted: 24 Jul 2015 at 1:03pm
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Improved power regulation I suspect, much in the same way it does with a phonostage or anything else James. My TT is direct drive but from reliabel freinds with external supplies advise me a good Power supply makes a difference, hence the reason L*nn etc attracts many after market go faster Power supplies (I am not ithe L*nn camp personally) but sure the emporers clothes would have been blown off if purelt a myth by now! Richard
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Posted By: Fatmangolf
Date Posted: 24 Jul 2015 at 2:55pm
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The basic Regas run off the mains AC supply via a transfomer to reduce voltage to 24 volts. Improved power regulation as Richard wrote and none of the spikes, FRI, and other distortions of the sine wave we are meant to get out of the mains. Worth remembering your cartridge will be fairly close to the motor coils and Rega don't ground the motor casing (worth considering if you're out of warranty).
The TT produces a clean 24 volt sine wave and I think my P3-24 sounds better with it than the supplied wall wart. It also allows electronic switching between 33 and 45rpm instead of taking the platter off and handling the belt.
------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 24 Jul 2015 at 3:14pm
Maybe I misunderstand your comments Jon but I get the impression that when you mention the benefits of using the 'TT' (presumably the TT-PSU) you do not link this to the incoming 24v AC from a power supply. It is the basic wall-wort feeding 24v AC into the TT-PSU/RP6 that I want to upgrade for the reasons mentioned by Richard (much as the Rega RP10 uses a more sophisticated power supply into the TT-PSU). The GSP PSU1 is an upgrade from the green power supply, I have a Speedbox touch with an upgraded linear power supply and now I want the same for my main turntable, possibly followed by another for the second. I have found an overseas source (& am visiting that country in 6 weeks so could avoid expensive postage) but would prefer something from GSP I note that Graham has offered to check a couple of things & he implies this could then be possible ------------- Older than I once was, younger than I'll be ............................. Andrew |
Fatmangolf wrote:Posted By: Graham Slee
Date Posted: 24 Jul 2015 at 3:37pm
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It will be 23 volts AC from the PSU1 transformer secondary. If you want to pop over when John is back (after 5th August) and drop him a line first getting him to wire the output to the transformer secondary, then you can take it and try it. Sorry I cannot oblige personally but I'm the skeleton staff (or soon will be a skeleton at this rate) and a bit hard pressed for the next week and a half. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: Drewan77
Date Posted: 24 Jul 2015 at 3:49pm
Thanks Graham but sorry to hear of your predicament  Yes, I will do that & send John a message ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 24 Jul 2015 at 6:16pm
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Apologies Andrew I missed your photo of the Rega 24V 380mA AC/AC adaptor. My TT PSU box is fed with the same unit and I appreciate now what you are asking. I hope the adapted PSU1 helps. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Fatmangolf
Date Posted: 24 Jul 2015 at 6:24pm
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I may open my TT PSU up over the weekend and look at the internal power supply circuitry. There may be scope to improve what happens to the 24V ac coming in from the wall wart. It would also be interesting to know the operating current for the motor to find out if the transformer may be limiting this. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Fatmangolf
Date Posted: 26 Jul 2015 at 5:12pm
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Having opened my TT PSU up I'm not convinced the 24V transformer is the limiting factor. If I wanted to improve the TT PSU I would replace the generic 1.000uF 50V smoothing capacitors and other parts with Rubicons or something similar. I would look at the voltage regulators as well. Together that might give a cleaner, more stable DC supply to power the 2 oscillators, the logic circuitry and the output amplifier that feeds the turntable's anti-vibration circuits and motor coils. Other ideas. Check the trim on the 'phase 33' and 'phase 45' presets to minimise vibration, there is a VE thread on how to do this. I also found that connecting a ground wire to the 24V motor casing in my P3-24 cut the hum picked up by my moving iron cartridge. Grounding the sub-platter via the bearing housing helped. I used a jubilee clip but suspect one of the RP6 braces may be metal and so is grounding this already. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 26 Jul 2015 at 5:42pm
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Thanks Jon, you are probably right although beyond what I am capable of so I will see if I can try out the PSU1-AC Graham suggests and then report back. I have sent John Cadman an email Neither of my MM cartridges produce hum on either turntable - both arms have separate earth leads to the studs on the Reflex M & Reflex Era Gold ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Drewan77
Date Posted: 11 Aug 2015 at 4:39pm
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I talked with John Cadman today and will be picking up a prototype PSU1-AC next week to try with the Rega TT-PSU. I will report back ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 11 Aug 2015 at 10:28pm
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Thanks Andrew. Do you have the old grey TT PSU I have from c2010 or the new version, please? ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 12 Aug 2015 at 9:45am
If successful, John says he can provide a toggle switch & two output leads to power both TTs independently. The Rega wall-wort output plug is exactly the same size as on the standard GSP PSU1. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 12 Aug 2015 at 8:47pm
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Very good service from GSP as always. Fingers crossed for the hoped for improvement in power regulation and speed stability. I asked in case you had the old version like my TT PSU. I considered doing a quick parts upgrade to loan to you for an AB comparison Andrew. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 12 Aug 2015 at 9:03pm
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Do you want to evaluate this after me Jon? ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 13 Aug 2015 at 5:43pm
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Ah, I wasn't hinting at that although If you don't mind I'll say yes! There's no hurry as I'll probably need to move my OL arm back onto the P3-24. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 13 Aug 2015 at 8:43pm
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That's fine Jon. I will collect it next Monday and am going away for a month at the end of the following week so John says its OK for me to hang on to it until End September/Early October. Let me know and we can sort something out when I'm back. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Drewan77
Date Posted: 26 Aug 2015 at 6:38pm
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I have been using the GSP PSU1-AC for the past week with both my 'new' Acrylic Rega/TT-PSU and directly into a 24v AC RP6-Planar 3 hybrid and
can confirm that it easily powers both at 24v. John C checked it out
for me at 245-252v (something within this range seems to be common in my house) and it
was outputting 25v. Music sounds rock solid with no noticeable wow or flutter, even on sustained piano notes so all is good. I haven't done any serious back-to-back listening vs the two original wall-worts yet, that will have to wait for a few weeks. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Drewan77
Date Posted: 05 Oct 2015 at 2:20pm
Picture of the PSU1-24vAC (rear) & Rega TT-PSU with twin turntable switch box (mounted in a PSU1 casing, LH side). A single 4 pin Kycon connector goes to the TT-PSU with twin 4 pin Kycon connectors to the PCB housing on each turntable. Measured with the Turntabulator app on both platters, the main turntable with a GT reference subplatter reads exactly 33.3rpm, the other with an aftermarket alu subplatter reads 33.4rpm. At 45rpm I get the readings 44.98rpm and 45.01rpm. Pitch is stable on all settings and I have removed two potentially 'noisy' wall-worts, replaced with the linear GSP power supply - also freeing up one wall socket.   ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 05 Oct 2015 at 9:29pm
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Nice. Your very good idea expertly delivered by John C. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Gijo1977
Date Posted: 09 Apr 2017 at 9:08am
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I would be interested to know if this prototype went any further into consideration for development, moreover, is it possible or plausible to have the one PSU1 supplying both the DC required for the Phono pre AND the AC for the Rega? (As you can tell, I know very little about electricity) I am pretty interested in the options to replace my Rega wall wart for the TTPSU, it has a terrible buzz from the back of my cabinet, and a reputable high quality option to replace it with is on my agenda, as well as a new phono stage. Thanks |
Posted By: Richardl60
Date Posted: 06 Jan 2018 at 6:38pm
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Hi, I may well be looking to upgrade the Power supply for my proposed TT purchase which appears to run 24V. I have browsed a little on the internet and there do appear options there R**s A*****s provide a pricey offering. Does the item discussed in the thread provide a viable option (sorry haven't got the full spec details as yet for my needs). Thanks
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Posted By: Drewan77
Date Posted: 06 Jan 2018 at 6:47pm
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Hi Richard I am still using this bespoke GSP 24v power supply & switch to run my two Rega based TTs. Superb speed stability & no audible wow/flutter or pitch issues to my ears. I suggest you contact John C if you are interested in another like this. Let us know how you get on.... ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Richardl60
Date Posted: 06 Jan 2018 at 7:10pm
| Many thanks |
Posted By: Graham Slee
Date Posted: 07 Jan 2018 at 6:59am
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Much as I hate to do this, the speed controller as described here: https://www.hifisystemcomponents.com/forum/turntable-speed-control_topic4359.html" rel="nofollow - https://www.hifisystemcomponents.com/forum/turntable-speed-control_topic4359.html ...would be ideal for 24 volts provided it's an AC motor. The next step in development is to have a 24 volt transformer made. Currently it only does 110/220V. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: Richardl60
Date Posted: 07 Jan 2018 at 8:01am
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Thanks Graham Will see if I can get the transaction through before looking at too much further. Apparently has a bespoke valve PSU. (Which I don't find appealing) plus the socket one with the deck. |
Posted By: Graham Slee
Date Posted: 07 Jan 2018 at 8:26am
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It's a MRM yes? According to this they did an AC and a DC version: http://4.bp.blogspot.com/-P55VrTR79T4/T2CCB33xmDI/AAAAAAAAALw/vxrpcQE0Z8s/s1600/source+circuit.JPG Great documentation...  And you definitely want one of those? I'm not sure if I can help. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: Richardl60
Date Posted: 07 Jan 2018 at 12:23pm
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I can’t access the link on a tablet so will have a look later on desktop thank you. It is the original MRM Source with AC motor. The later S.O. Was produced more on a budget had the DC motor. When my brother bought his from new it was superb and as it was the Luxman he moved up from it should be a known quantity so far sound goes, accepting the trade off of convenience and in some ways ease of use of the DD Luxman. |
Posted By: Richardl60
Date Posted: 07 Jan 2018 at 12:58pm
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The Legacy website does have a little info re the motor.. http://thesourceturntable.blogspot.co.uk/search/label/Papst%20GS%2038-09" rel="nofollow - http://thesourceturntable.blogspot.co.uk/search/label/Papst%20GS%2038-09 Some further info in Vinyl Engine. https://www.vinylengine.com/turntable_forum/viewtopic.php?f=18&t=13802" rel="nofollow - https://www.vinylengine.com/turntable_forum/viewtopic.php?f=18&t=13802 |
Posted By: Drewan77
Date Posted: 07 Jan 2018 at 4:42pm
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A question for Graham - you mention the link to the speed controller thread but why might I need one of these please? I am not sure what benefit this could bring to my setup. The modified 24v AC PSU1 powers a Rega TT-PSU which is switchable between two turntables (thanks to John C) & as mentioned earlier in this thread, both measure stable at 33.3 & 33.4RPM with absolutely no pitch or w&f effects that I can detect. I am a very picky listener so I must admit to being mystified about why I might need a different speed controller  ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Graham Slee
Date Posted: 07 Jan 2018 at 5:02pm
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So, the motor and control circuit are as described here: https://www.google.com/patents/US3873897" rel="nofollow - https://www.google.com/patents/US3873897 The starting current found here: http://3.bp.blogspot.com/-IJQ7RXGMUs4/UYpup_YReuI/AAAAAAAAARg/huggXCpIYKQ/s1600/spec.png" rel="nofollow - http://3.bp.blogspot.com/-IJQ7RXGMUs4/UYpup_YReuI/AAAAAAAAARg/huggXCpIYKQ/s1600/spec.png ...is 240mA at 22V. The maximum power is therefore 5.3 watts plus a tiny amount for the control circuitry. The forum commentators suggest the use of a 30 VA (rms watts) transformer here: https://uk.rs-online.com/web/p/toroidal-transformers/2237822/" rel="nofollow - https://uk.rs-online.com/web/p/toroidal-transformers/2237822/ Comments seem to suggest that the higher the power of the transformer the better the sound will be. So maybe it is better to use the 30 VA transformer. As for the motor itself, it is DC. The supply can be DC or AC. The AC version has a bridge rectifier input to convert AC to DC. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: Graham Slee
Date Posted: 07 Jan 2018 at 5:07pm
I suggested it for Richard but then found it would be unsuitable (see earlier post). I am not trying to sell you a controller as I assume you already have one made by Rega. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: Drewan77
Date Posted: 07 Jan 2018 at 5:30pm
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Thanks Graham, I realise my post implied that I might not need one of these which isn't really what I meant to say. As someone who has only owned belt drive turntables I suppose I should listen and compare to something like the new Technics SL1200G which gets impressive reviews from trade and users alike. Maybe this would enlighten me and give a proper reference. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Graham Slee
Date Posted: 08 Jan 2018 at 7:14am
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Nothing wrong with belt drive unless the belt snaps. I've heard there's a problem with DDs cogging, but surely I would hear it in some way? I have three old (by now) SL1200's and haven't heard it. So nothing wrong with either BD or DD. The differences are due to construction. A heavy TT always sounds better to me, but I don't mean the platter should be as heavy as a van wheel. I heard it said that the Rega Planar 3 is the poor mans LP12. A customer brought in his LP12 for a phono stage demo, and the difference was night and day. The tonal range was complete. The Rega only does the top end because the mass is missing. That's why they tell you to mount it on a stiff shelf bolted to a masonry wall, which adds sufficient mass. At Heathrow 2003 I couldn't get sufficient bass with the Rega on the stand, but then I stood it on the concrete floor, what a difference! ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: morris_minor
Date Posted: 08 Jan 2018 at 8:59am
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I've three DD turntables in the house at the moment and have had more - and I've never heard cogging. The acid test was when I still had my GyroSE and I bought a little Technics SL-7. With the same cartridge (in a p-mount adapter on the Gyro) I did some comparative rips. With someone else switching between them so I didn't know what was playing I couldn't reliably tell them apart. The SL-7 weighed far more than it looked, and of course the Gyro had those mesmerising brass weights . . . ------------- Bob Majestic DAC/pre-amp Accession MC/Enigma, Accession MM, Reflex M, Elevator EXP, Era Gold V Solo ULDE, Novo, Lautus USB and digital, Libran balanced, CuSat50 2 x Proprius + Spatia/Spatia Links |