Rach needs your help !!!!!

EDIT 4-27-2015:
Many thanks to you all, from Israel, Australia, France, Switzerland, Canada, Ucraine, Romania, Germany, Taiwan, Italy, USA, Spain, NL, Hong Kong for your kind donations…you know, who you are 😀

Target is reached, but feel free to continue supporting me 😀

Dear friends, for some months I had temporarily problems coming from my amp unit, the Luxman 55A. Sometime I lost one channel (mostly right) for some seconds up to several minutes…sometime both channels are “sleeping”. In such cases, when I am ripping, of course I have to start the rip again, hoping that this doesn’t happen again. Normally it occurred only 2-3 times daily, but in the last time it comes too often, so that I cannot rip properly like you know it from me. In a word, it’s almost impossible to rip properly.


I brought my beloved vintage amp to the service, working for 2 weeks with a cheap reserve amp from an obscure Chinese company, Synn C-08 (by far not as good as the Luxman is). The approx. costs for the repair of the Luxman will be around 350 EUR.

Please, if you feel, you can help, donate for this cause. 5, 10, 50 EUR or even only few coins, no matter what, every Cent will help.

Please enter one of my posts, scroll down and use the “DONATION” button.

Thank you very much.

49 thoughts on “Rach needs your help !!!!!

  1. Alfred, Many many thanks for all your work, 10 Euros on the way from Mexico City.

    Saludos and again thanks for all this wonderful rips.


    • This is not sure…it could be a simply “mechanical” problems of the potentiometers/relais…I don’t know. They didn’t say yet, what it was….I only know they said me the most of the costs is for dismantling the amp, in search of the problem.

    • Removing big capacitors isn’t so easy because of low place on the PCB board. Audio grade high value caps are mostly big ! Changing capacitors may also degrade sound quality if new ones are lower grade. This operation should be done wit care ! It may be only a “dead”, dry solder on a component located in the warmer area of the PCB board. Try to gently slap the top of the device while in use to see if it makes the problem disappear and appear.

      • The big annoying problem is, you can have the issue just minutes after switch on…or never in days, then suddenly….and another additional strange “thing”: often, if it happens, the signal is lost and I don’t hear anything, but sometime the signal is there (I see the wave continues, on the PC but I don’t hear it…or viceversa. But this last is very seldom. More is the lost of signal, visually and audio. But is not a regularly issue. It happens absolutely chaotic in time and duration. The best I had was about 2 weeks of fantastic music without a problem.
        GodIsInTheRadio brought my attention to an old-school-magician (technician) in Berlin. I contacted the man, waiting for info.

        • Random issues are typical of bad solders. Did you try to remove top of unit and bring light vibrations by gently knocking PCB with a pencil to see if it happens issue or remove it ? BTW do this unit get warm in use or just tepid ? If I well understood you only use the Preamp funtions (not Power function) : you enter in Phono terminals (1 or 2 ?) and go out from PreOut terminals to your Mono Amplifiers and ADC unit ? Do you get the same problem listening to rips or is it only LPs ? This question could help to locate the defective area. I suppose your DAC output is connected to AUX terminals, isn’t it ? Pity I can’t investigate inside. Wait some days before going to the service, we should be able to solve the problem ourselves, let us be patient.. 350€, shit !

          • jean-Luc, brother…I do the hell removing something to try some other things 😀 I get older and – premise is, that I’m not the greatest “technician” here – I simply fear to do anything because I suffer of light shaking….very light indeed, but it makes me insecure to do something I’m not knowing.

            The issue occurs in some different ways, as I wrote in the last msg. Mostly is, when the audio drops out, also the signal to the PC is interrupted….but not always, and this is what makes me fear, there is a real beast of an error in the amp.

            I don’t use the phono 1 or 2, simply because they are not that good as my Pro Ject phono amp is.

            The chain is this:

            TT(Yamaha) —> Pro Ject phono amp —> Luxman 55A (one of the high level entries) from the tape monitor (out) —> RME Fireface UC / MAC

            And yes, the amp is always very gentle a little warm….you can say, it increases the temperature no more than few C°….as you wrote, I use only the pre-amp section. I never tested the main amp…

            • So the problem isn’t located neither in the power amplifier area nor in the phonos area, but in the 40% remaining area of the unit. As it is old it could also be dust in a connector which would bring sporadic bad connections. But don’t be afraid : I’m sure it’s almost nothing. Don’t trust what you see on PC : it’s software…It may sometimes locks on last good state of the signal, if you connect the PC to the same point where Fireface is connected it’s simply impossible to get signal on PC screen and lose it on Fireface. The only trustable tool is the oscilloscope ! Today I studied the schematic of the unit and I can say that the preamp area is well designed though we can’t know grade level of capacitors (we can’t see on photos), I’m not sure they’re high grade audio because of age of the unit. Replacing them (especially the output one) would IMHO increase significantly sound quality. And also phono stages should be disconnected if unused because they share the same power supply than the preamp stage and I assure it’s really a bad thing because they bring noise on shared power supply which means LOSS OF CLEARNESS ! Some years ago I made these changes (and some more) on several preamplifiers and the improvement was STUNNING ! But I’m not sure that people on the service will accept to do that… Alf you should rather go to an independant technician, anyway keep us informed.

                • Sure ! I thought about it but I thought that the heavy weight could be an obstacle. But may be UPS for instance will carry it to me.

                • I got an important question : when the issue occurs in which postion is the “Tone Bypass” switch ? Tone Control Operating or Bypassed ?

                  • Something I’ve overlooked: If I don’t let repair it there, where the amp now is, I lost 80 EUR of costs estimating…
                    HM….what now?

                    • OK OK now I see better the problem, we go forward. So tell me if I misunderstood :
                      – You only use the ADC section of FireFace, never the DAC one because you don’t listen to Flac music.
                      – When you rip you adjust level of signal on Fireface, NOT on L55A.
                      – When the issue occurs you can’t know if it also occurs at the end of chain (big speakers).

                      So now an important question : does the issue also occur as you listen to LPs through the chain Pro Ject Phono –> L55A –> Mono Power Amps ?

                    • – You only use the ADC section of FireFace, never the DAC one because you don’t listen to Flac music.
                      – When you rip you adjust level of signal on Fireface, NOT on L55A.
                      On 55A I cannot set any level…the signal goes only through the 55A because of listening possibility. There is no possibility to manipolate the tone, nor to set some level. I set the level for ripping on the RME, but not phisically (not on the engine) but virtually on the program Totalmix, that was installed when I start to use the RME
                      – When the issue occurs you can’t know if it also occurs at the end of chain (big speakers).
                      Is definitely the amp, as far as now, for almost two weeks, the cheap chinese amp works perfectly and the issue never occurred. The issue also never occurred before I had the 55A, more than 1 year before….you can see on my rips, when I changed the amp.

                      So now an important question : does the issue also occur as you listen to LPs through the chain Pro Ject Phono –> L55A –> Mono Power Amps ?
                      of course, yes….ripping+listening or only ripping or only listening, the issue occurs.

                    • An additionnal question :
                      FireFace is connected to Tape out 1 and PC to Tape out 2, aren’t they ? It would explain why you lose signal on rip while keeping it on PC. If you reverse these 2 connections, almost sure that PC will lose signal instead of rip ! We approach Son !

                    • NO… RME is connected only with Tape out, nothing more.
                      Another thing: occasionally I have to rip some cassettes for my customers. The “issue” doesn’t occurres, NEVER! So the Tape Out cannot have something to do with the problem.

                    • Well well well.. but to rip cassettes you connect to Monitor (1 or 2), don’t you ? And the path inside unit Monitor1–>Tapeout2 (or Monitor2–>Tapeout1) isn’t the same as Aux1/Aux2/Tuner–>Tapeout1/Tapeout2 !! I have schematic in front of me. It would explain why issue only occur with LP and CD !
                      Where does the PC take the signal ?

                    • The outgoing signal from the phono amp is always there. The outgoing signal of the tape is only activated by switching to Tape 1. I don’t use 1->2 or 2->1
                      Very puristic: all knobs of tone control and filters set to zero, all other switcher out. Use only Aux1 and Aux2. When I need the tape signal I switch Tape 1. That’s all.

                      And yes, Tape INput for 1 and 2 are like Aux 1, 2, Tuner. On TUNER I had the issues. On Tape 2 no…but this doesn’t means it worked. It means, the short time I tried it there were no issues. On the AUX1, 2 and TUNER I also had several weeks no issues.

                    • It’s a maddening bug for from sources Inputs downto Tape1OUT there are only wires and switches !! The musical signal doesn’t meet any component (except an input parallel resistor) : balance, volume & filters only operate downto Mono Power Amps, not downto RME.
                      The L55A area which is defective is a kind of matrix in which the musical signal from several inputs finds its way downto Tape1OUT and also unfortunately probably picks up noise. Aux1/2 & Tuner inputs are put together in an analog bus which runs a wires path while Tape1IN runs a different wire path, each path leading to Balance/Volume/Filters section and to Tape1OUT connected to REM input.
                      Therefore issue may occurs to Aux1/2/Tuner (and therefore will occur to all three) while not occuring to Tape1IN. The chronological path (according to schematic) is : switching from Aux1, Aux2 & Tuner wires (“Input Selector Switch”) into a single wire which then runs downto “Monitor Switch” where Tape1IN & Tape2IN wires also runs, this 2nd switch feeding then Tape1OUT, Tape2OUT & Balance/Volume/Filters section.
                      So if shit stands uphill “Monitor Switch” Tape1IN will work fine. For instance if “Input Selector Switch” common pin is half broken or its solder on PCB is dry the unit will bug exactly the way you describe. It’s the reason why it’s important to check a while Tape1IN behavior.
                      I don’t understand why straightly connecting RME to the Pro Ject Phono output (which is connected to L55A Aux1) instead of L55A Tape1OUT shouldn’t work, the signal is the same ! Everything would be easier, this RME is a magic box and can do everything ! It would be able to substitute with benefit your L55A.

                    • I don’t understand why straightly connecting RME to the Pro Ject Phono output (which is connected to L55A Aux1) instead of L55A Tape1OUT shouldn’t work, the signal is the same ! Everything would be easier, this RME is a magic box and can do everything ! It would be able to substitute with benefit your L55A.

                      Jean-Luc, I never said it doesn’t work. Of course it works, but in that case I have no acustical monitoring…means, I cannot hear anything. I see on the computer that the signal comes, but I can hear it only on post-processing, after recording. The reason why I have the 55A switched between RME and Pro Ject is that I want to hear…like 2 billions of people worldwide have an amp…for listen to music.

                    • I have now the amp again here at my home….I will set the Pro Ject on Tape 1 IN and CD player on Tape 2 IN….when I need to rip cassettes for customers I can change with the CD player.
                      Give me 1 month of testing and end of May we know, if the amp stays here….or it comes to you. Maybe the issue occurs earlier – although you mean it’s near impossible on Tape 1+2 …..so I send you the amp before end of May.

                    • Perfect ! Let’s keep watch the patient.
                      Anyway even if it bugs in this configuration it will help me to investigate.
                      As for RME you can connect headphones on front side and last but not least your Mono Amps to an Output. The preamp section may be better quality than L55A, it’s really a way to explore I think. BTW all RME inputs are balanced and L55A outputs are unbalanced : do you use an adaptator ?

                  • So Tone Switch is depressed (bypassed) meaning that if you correct trebbles or basses no correction occurs in the sound, doesn’t it ? Excuse me to insist but it’s important and we have to be sure.

                    • all four knobs for tone manipolation are at zero (notch at 12 o’clock position) bass boost is off, filter is off, loudness is off, therefor the bypass was never important to me. I never liked to alterate the tone, with the bass knob and high knob. Seldom in life, when the actual amp I owned had a loudness knob, so I used it in the night or even when the music was absolutely bad. Never used anything on this Luxman. In the past, most of the amps I had, didn’t have tone knobs. This is the way I love an amp.

                    • I agree with you : all amps and preamps should be done without filters and boosters for even when they’re unsued, signal gets noise & distortion through filters & boosters switches ! But the Tone Switch here is very useful for depressed, it allows signal to bypass trebles and basses filters stages (which are heavy) and therefore to go straightly to balance & level controls and then to go out : in this way sound should be improved and moreover if ever this f****** bug stands in bypass stages we could bypass it !!! IMHO it’s really a thing to check !
                      Second thing : in fact this amp is used in your rig only to set level (there’s not even signal preamplification through it) ! So you should try to connect straightly the RME FireFace to the Pro Ject Phono amp balanced outputs and set level on FireFace. You could be nicely surprised of result.. IMHO the L55A here is useless and redundant.
                      Third thing : you should bring back your unit from the service. 80€ just to tell you “we can fix the problem for 350€ more” is a lucrative job.. In last resort I’ll fix it !

                    • OK, I will pick up the amp and send to you. Concerning what you write, about connecting the phono amp direct with the RME…I know, and I tried it somewhen, but in that case I cannot hear anything, despite the noise-called-music, that comes from the mac. In fact the Luxman is a re-direction unit for the signal and, at least, for me when I want music without ripping.

                      Anyway, I will send it to you and prepare myself to convive some weeks with hard sounding music from a cheap chinese amp.

                    • All this puzzles me. Do you mean that FireFace analog output goes back to L55A ? Could you please describe the full connections from Pro Ject Phono amp downto dual Mono Power Amps with name & number of all connectors used and also the way you listen LPs without ripping and the way you listen rips (already done). I need to see the full chain.

                    • OK…the chain is this:

                      TT(Yamaha) –> Pro Ject phono amp –> Luxman Aux 1/Tuner…and…from Tape out to –> RME Fireface UC –> iMac24

                      I had the Pro Ject connected to AUX1 and a short time to TUNER….both had the described issues. On AUX2 is connected my CD player and also here, sometimes occurs the described issue. When I hear and rip or only hear or only rip, nothing is changed.

                      I don’T have the possibility to hear through the equipment what I rip, because equipment and Mac are in two different rooms. I hear/control/post-process the rips with a headphone, connected to the output of the RME.

                      I repeat: when the error occurs and I lost the signal on the PC is less times as when I only don’t hear a channel. Try to explain better: when a channel drops out, not every time I lost the signal on the PC. Indeed, this occurred (lost audio+signal) only few times in the last 5-6 months…but more than 4fold/5fold I only lose the channel without losing the signal.

                    • In addition to what I wrote before: The RME is never connected via analogue OUT to the 55A. I tried in 3 years I own the RME only twice to hear some rips I had downloaded…but normally I don’t have the time to do it, so the RME is never connected, concerning OUT.

        • hi,

          this is avi kujman from israel. i gave you 60 euro the last day. please, let me know if you need more. no problem. it is nothing against your job!

          • Thank you my friend, for your generosity. If for another 2 days some good souls will contribute like the first 2 days, it would be OK.
            Thank you for your offer, I will let you know 😉

  2. Do you know Dieter Künhold? He is the guy to go to if it comes to Luxman amps. A wizard: http://www.luxman-forever.de/kontakt.html

    I was there two times and two times very pleased. A real old-school technician and he has many, many original Luxman vintage accessories / replacements there. If you’re going to Berlin, you can even drop things there…

  3. Dear Rach.,
    I do Plan coming To Munich in the next days so I can bring with me all my repair equipments needed to investigate and fix the problem of Your amp at Yours Place, No need for You to send it anywhere. You only have to provide a table, some good table light, everything else is on my account.
    How fare are You living from Munich?
    Please send me a PM.

    With my best Regards,

    • dear Jan, thank you very much…you don’t need to come, bringing me your help. For this alone I would drink with you a barrell of beer 😀
      I told Jean-Luc that for now the amp, with my TT in a Tape-IN works perfectly and I will (I must) let it for now, also because I have horrible much work and the place around my equipment is full with hundreds of records I rip every day…I had last November a big order of about 1600 items (will be real about 1800 records). Dead line is around September this year and I have to rip more than 1/3. Anyway, I have always two reserve amps here with me…now three, thanks to a user from NL who send me for free his old-but-good unit.

      Thank you again my friend, but I decide after September what to do…

      PS: I live around 500 KM away from Munich….the banks town, you know? Draghi’s residence…little New York 😉

      • Great to hear It is working now, but as I understand Yours current working gear You use the Luxman amp only for input monitoring, no actually gain stage is involved in signal pass true to the Yours Mac, the only active stage is perhaps the Phone out, which is in parallel with the main IN pass through signal to Your RME card. Can You make a Leveling the Output Signal to the RME with volume potentiometer or is this function only available to Yours Headphone output ? How do You listening the music while not ripping ? CD Out or AUX out to Your external amps, is the Volume leveling available to this playback route? but I think the signal is only routed as a line out at 2V to +6dBU AC out to external stages so this is a separate Line Out or PreOut which is actively amplified? Will try to get a SCH to see how it route the Line and PreOut signals to see it how exactly it manage its Line level signals. If The taget for using the Luxman mp is only managing the passive way of line level signals then I’ll design one for You for the exactly Yours specific purpose with special balanced line out Buffer, for shortest direct feed to RME and Buffered feed for the phones also straight & shortest paths. A Hi Q parts will be used exactly where needed. You just specify what You have connected, how do You route the signals and the Target-destination send of the Phono signal – voila – this way the sound purity will be hard to surpass with commercial stuff. Maybe I’ll poison You with my own design and build a LiPolimer batt. powered MC-Riaa all balanced pre with +6dBU class A output feed . .
        Btw. I’ll be this Saturday at HiEnd show in Munich, if You visit it also, we can really put down some heavy big glasses of Löwenbräu . . .

        With my best regards

        • Yes Rach uses only the passive way of his L55A, monitoring for ripping and LR_balance/level controls for listening. You can find schematic here : http://www.hilberink.nl/luxman/l55a/luxman-l55aamp.pdf . I think there is something wrong in the area of the Input Selector switch, the hardest work is to get the unit ! It’s a TRUE GOOD IDEA to think about building a customized preamp for his needs. To get balanced outputs I suggest the Sowter 9335 transformer : http://www.sowter.co.uk/transformer-attenuators.php .
          With this High-Grade transformer in the same time you can control level (0dB downto -48dB) and you get full galvanic isolation with RME and Power Amps.
          You could include in the same unit as you suggest a MC-RIAA preamp that you describe (class A without chips..) which could sound still purer than the Pro Ject Phono which uses only chips in active stages and in particular a high current buffer stage becoming useless if the unit is integrated in an overall preamp.

  4. Dear Jean-Luc,

    Thnx for the Luxman SCH link.

    As I can see from the SCH in the IP. section the Signal feed – AUX IN has the Shortest & straightest – Signal Path to the REC Out, all the rest were affected by balance and vol. potentiometers If the active Line Level stages were bypassed along with the tone control buffer, the resulting pre-out is really a passive only with substantial loss of signal through the I/P via Routing Signal switches + balance + vol. potentiometer.
    All These locations are the possible sources of the discontinuation to the SIGNAL – Mr. Rach mentioned
    The reason could be also the oxidation, Lose of the galvanic coating on the selector switches and also the the dirt on the wiper contacts within the potentiometers
    – but I suspect the most common problem could be some cold joint on some of the selector / routing contact or even more possible would be Dirt on a main vol. poti. wiper contacts or a bad (wear out) Solder Joint due to it’s most frequently use, it is also way much more prone to mech. wearing.
    My Proposal – The Quick Cure:
    – Disassemble the Amp, Carefully investigate the signal flow routes, make a macro photos of suspicious places, and preview the photos on a larger screen, with a greater zoom on the critical points many hidden things will be visible . .
    Then It is possible to analyze the investigating phase with just a simple Beep Continuity Diode tester on any DMM meter to quick evaluate the possible Failure with just following the signal flow from the I/P Connectors with use just a little force – pressure, maybe a slight movement of each soldered pin or Lightly flip on it with the Screw Driver grip on to each contact all along the way with signal flow direction. Even without a scope is easy to found out the weak – bad, or loosened continuity Contact – eg. loosened contact on some solder joints on a PCB board/s if they’re not wire-wrapped
    – Further is need to be to desolder and remove from PCB Board – both the balance & vol. potentiometers, then each of them need to be very carefully disassembled to single pieces ( Wiper + Resistive Element), carefully inspect them with a 2-4x Loupe and further mechanically hand cleaned them – all wiper contacts and especially the resistive parts of the potentiometers best with a pure cotton buds – lightly liquid-ed with the Contact Clean Gold 2000 – it is based on the isoprophil Alch. – very effective cleaning is achieved with it.
    – Then after Detailed Cleaning all mentioned surfaces it is needed all to be further lightly Polished – best with the dry (glasses small micro fibre cleaning towel).
    Then all Pieces Should be Carefully assembled back together, and resoldered back into theirs previous places, Finally also desolder – resolder all Other contacts from RCA Inputs all along to their respective outputs, . . .
    Done . . It will function (the Amp) as NOS. for the next decade. . .
    End of Cure. 🙂
    If To be Avoided any further similar malfunction with the Lovely vintage Luxman Amp then . . .

    The Very Quick & Doable Fix solution would be:

    eg. Me To design and build for this particular purpose The New, I\P Selector – and a full Balanced Differential all discrete – Line Level Buffered Class A feed for the Direct Line Out feed to the RME AD Section, + optional O\P Routing Switch maybe if needed, I don’t really know how much it’ll be needed ?, + additional Active feed with vol. pot. for the phones – SE Line Out – and all packed in a nice Black Case . . .
    Would be the The Quickest – HiQ Quick fix for the current Rach Ripping situation.
    To Build a Whole new Phono-Pre ? . . by my standards is quite a diy project, if interested I’ll explain it in the next post If You like.
    With my best regards,

    • None a potentiometer can’t be suspected for issue wouldn’t affect ripping, only listening ! Indeed TapeOut is used for ripping as PreOut is used for listening. The issue occured using Aux1/2 & Tuner, never occured up to now using TapeIn1/2 (Monitor1/2 on schem) so all suspicions seem to be turned to Input Selector area.

      Beware of adding Line Level Buffered Class A feed for the Direct Line Out feed to the RME AD Section : Alf’s way of using his preamp makes it a full active stage free preamp.. IMHO the most Hi-Fi way of balance unbalanced outputs remain transformer.


  5. I thought a potentiometer is to be suspected only for a listening – monitoring conditions while ripping – (Phones feed) – as there’s the the line buffer to assist the Pre-Out, – – The transformer is indeed the simplest conversion fro SE to Bal. feed, but then need to be special order to closely match RMEs I/P el. parameters for a direct feed without any additional compensations needed, resulting in introducing unnecessary new poles.
    But the monitoring eg. with phones or an xtra feed to power amps still need to be buffered to max. unload-release the main signal feed to the RME AD for the lowest phase shift to its I/P section at least while Ripping.
    The best to take off the signal for the bal. transformer and add. buffering would be at the signal input before any I/P switching – and then routing through switches & vol. pot. only the buffered signal to minimize signal loses.

    With my best regards,

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