Les, you are a man of great integrity, and I really appreciate your offer but I'm happy to say that I am currently listening to a wonderful 1965 RCA Red Seal recording of Stravinky's Firebird Suite by the Boston Symphony Orchestra. A friend happened to have some Sylvania blackplate 5751 tubes that he was willing to let me borrow. I have to say this recording has never sounded better. Next up is Allison Krauss's Paper Airplane album.
I had hoped that a simple change of tubes would provide the solution to what I was hearing and I can now say that I am very happy with what I hear.
I had hoped that a simple change of tubes would provide the solution to what I was hearing and I can now say that I am very happy with what I hear.
MAD about my 23B (and I mean "MAD")
Hello everyone,
This is my first post in this forum. Should I have introduced myself somewhere else first?
Well, I am writing this because I am the ¿happy? owner of a Yaqin MS-23B. My unit has "THE HUM" (why oh why?) and I have tried almost everything suggested earlier in this thread with no results whatsoever.
I have to say that I have not tried the "69" circuit solution yet nor Les's conversion because I am a total nerd when it comes to electronics. --I see that there are some brave individuals out there who have done this with no previous experience using a soldering iron but, honestly, I think I'm not one of those. Also, I live in Europe, so I guess that sending the Yaqin to other continent to get this fixed by someone else is not an option. --Or is it?
I would like to thank Les beforehand because probably someday under the right conditions I will do his mods to my unit anyway, especially since everyone around seems to be so happy about it, but now all I want (after one month of suffering the hum...) is to throw the Yaqin thru' the window. At least I'd get rid of the hum forever I guess.
But since this would deprive me of listening to music as well I think that the questions are:
1) Is there any way to get rid of the hum (completely) without doing the Les's mods?
And just in case the answer is no:
2) Do you honestly think that someone who knows NOTHING AT ALL of electronics could do something like Les's mods... on his own?
Thank you all,
Hugo.
Hello everyone,
This is my first post in this forum. Should I have introduced myself somewhere else first?
Well, I am writing this because I am the ¿happy? owner of a Yaqin MS-23B. My unit has "THE HUM" (why oh why?) and I have tried almost everything suggested earlier in this thread with no results whatsoever.
I have to say that I have not tried the "69" circuit solution yet nor Les's conversion because I am a total nerd when it comes to electronics. --I see that there are some brave individuals out there who have done this with no previous experience using a soldering iron but, honestly, I think I'm not one of those. Also, I live in Europe, so I guess that sending the Yaqin to other continent to get this fixed by someone else is not an option. --Or is it?
I would like to thank Les beforehand because probably someday under the right conditions I will do his mods to my unit anyway, especially since everyone around seems to be so happy about it, but now all I want (after one month of suffering the hum...) is to throw the Yaqin thru' the window. At least I'd get rid of the hum forever I guess.
But since this would deprive me of listening to music as well I think that the questions are:
1) Is there any way to get rid of the hum (completely) without doing the Les's mods?
And just in case the answer is no:
2) Do you honestly think that someone who knows NOTHING AT ALL of electronics could do something like Les's mods... on his own?
Thank you all,
Hugo.
Have you done this mod at the jacks? This should cure the hum.
http://www.diyaudio.com/forums/tubes-valves/216979-yaqin-ms-22b-phono-amp-7.html#post3384759
While your in there do the whole thing, third tube and all,
I'm pretty sure that you won't regret it. Numerous begginers have
completed this conversion and I know it seems a bit intimidating
at first, but drain the capacitors of energy, follow Les's instructions
and you'll be fine. I don't want to speak for Les, but I know that
he'd be glad to walk you through it, and if it is "too much" for you,
I'd bet that he would see to it that you still end up with a LesBox.
http://www.diyaudio.com/forums/tubes-valves/216979-yaqin-ms-22b-phono-amp-7.html#post3384759
While your in there do the whole thing, third tube and all,
I'm pretty sure that you won't regret it. Numerous begginers have
completed this conversion and I know it seems a bit intimidating
at first, but drain the capacitors of energy, follow Les's instructions
and you'll be fine. I don't want to speak for Les, but I know that
he'd be glad to walk you through it, and if it is "too much" for you,
I'd bet that he would see to it that you still end up with a LesBox.
Thank you for your reply lilc.
Yesterday, a friend of mine came home and helped me unsolder the inputs away from each other. Now I have opened the Yaqin and I've found this:
Well obviously the wires are attached to the wrong channels, so I've grabbed the ironing solder (for the first time in my life), I have corrected it and now the hum is almost gone.
I have to say that it is "almost" gone only if I disconnect the PCB ground wire from the chassis, otherwise I get the same hum noise level. Does this make any sense anyway?
I have a Rega RP3 and as you know it carries the ground via the RCA's, so maybe this has something to do with the hum too?
Thank you.
Yesterday, a friend of mine came home and helped me unsolder the inputs away from each other. Now I have opened the Yaqin and I've found this:
An externally hosted image should be here but it was not working when we last tested it.
Well obviously the wires are attached to the wrong channels, so I've grabbed the ironing solder (for the first time in my life), I have corrected it and now the hum is almost gone.
I have to say that it is "almost" gone only if I disconnect the PCB ground wire from the chassis, otherwise I get the same hum noise level. Does this make any sense anyway?
I have a Rega RP3 and as you know it carries the ground via the RCA's, so maybe this has something to do with the hum too?
Thank you.
Terry, just seen your reply after contacting Tubestein. I have not ordered the replacement yet so if you are happy with the LesBox then all is fine.
Bechstein: Try and remove all grounds from the cartridge leads if you can, run ground free cables to the RCA inputs and this should remove any hum loop problem you are having.
Postage cost should be a lot lower if you want me to do the conversion here in the UK.
Bechstein: Try and remove all grounds from the cartridge leads if you can, run ground free cables to the RCA inputs and this should remove any hum loop problem you are having.
Postage cost should be a lot lower if you want me to do the conversion here in the UK.
Thank you Les for your suggestions. I have just sent you a PM.
Thank you dady, I'll send you a PM right away.
I have one of those and while a decent cart, I would recommend the Denon DL-110, more money but you will not regret it. BTW, it works well with the LesBox.
Hey all. I'll be selling my fully Lesboxed MS-22B shortly and I thought I'd offer it here first. I have the opportunity to upgrade to a fairly high-end phono preamp at a great price so I thought I'd pass along this lovely sounding preamp to the next lucky guy.
PM me if interested please.
PM me if interested please.
An externally hosted image should be here but it was not working when we last tested it.
So, I finally made time to christen the new workbench and set to work on the LesBox conversion. Read and re-read the instructions, checked all components, dremel, solder sucker etc were to hand and tentatively but confidently opened her up. The track cuts were checked and re-checked and the c3a/c3b/RAG/RAF arrangement was by far the trickiest until I stepped back and regained the patience required! Drilling the hole for the third valve is indeed the point of no return, but my old cabinet maker friends mantra ‘measure twice, cut once’ guided me through. My 23 had the left input negs joined together so they were separated, the extra earthing was put into place and it was time to test. Things were looking good as I worked through the checklist – after all I had checked everything I had done before moving on to the next job. But then, j) V1 pin 7 to ground – nothing! How is this possible?? I carried on and now o)V2 pin 2 to ground – nothing!! I carried on but q and r – also no reading. I checked the circuit diagram and started testing track and components but all seemed good. Then I realised – the last time I used my multimeter was about 8 years ago before I left the UK – batteries were almost dead. New batts in and she sailed through the tests so we closed her up, peeled off the protective masking tape, polished her up, loaded the Svets and paraded her through the house to The Vinyl Room. Minutes later she’s wired in to the Garrard and it’s power up time. Horror! Hum. Not a little bit but huge amounts. Checked the TT/Amp earth tags and all is good. But no, still an almighty hum. Disconnected the TT, still the same. Tried a test record for a quick signal check and had the humming AND distortion. Then it hit me...schoolboy error – had the LexBox plugged into the Phono input...
So after a quick swap to a spare Aux input we are ready to go. So what to play first? As it happens, a couple of well wrapped boxes had arrived a few days ago from Pop Market and Amazon, so 1st up was a brand spanking new 180 gram Dark Side Of The Moon. Plenty of range changes and of course a familiar album (I was saving the special 2nd box till my ears and brain could understand what this little box of tricks was giving me).
Well, what can I say – instantly I could hear the difference in volume (I kept the 6db gain in), but I’m amazed how pokey this thing is! The clarity is a whole new level and the bass – my B&W’s sounded like subs! I’m grinning and I’m only on side 1. Side 2 and it’s still getting better My ears are getting tuned in to this luxury sound and it’s like my turntable, amp, room, sofa, everything, is a brand new thing! The reports of the soundstage developing more dimension, the space between the mixing channels and the closeness of the band to you are all spot on. Just amazing.
But I can’t wait any longer – I’ve got to get the ‘special 2nd box’ contents out. I’ve been waiting for this a long time, it was always the plan to give this it’s first play on the LesBox. So here we go, flicking through the options in my shiny new The Beatles In Mono boxset. Not the nasty ’09 digital effort, but this years all analogue extravaganza. Revolver it is. 3 hours later and I’m still buzzing! This beautiful, inspired, personal gift from Mr Carpenter is beyond words. A revelation has occurred. The new mono albums are a superb piece of work and this little MS23 LesBox has taken them beyond any previous level of aural pleasure.
So, not the most technical of reviews, but nonetheless, a HUGE thank you to Les for designing and sharing this masterpiece. Thank you for re-igniting my DIY enthusiasm, and thank you for putting The Beatles in my room as opposed to just in those speakers. I can’t wait for tomorrow to start all over again.
So after a quick swap to a spare Aux input we are ready to go. So what to play first? As it happens, a couple of well wrapped boxes had arrived a few days ago from Pop Market and Amazon, so 1st up was a brand spanking new 180 gram Dark Side Of The Moon. Plenty of range changes and of course a familiar album (I was saving the special 2nd box till my ears and brain could understand what this little box of tricks was giving me).
Well, what can I say – instantly I could hear the difference in volume (I kept the 6db gain in), but I’m amazed how pokey this thing is! The clarity is a whole new level and the bass – my B&W’s sounded like subs! I’m grinning and I’m only on side 1. Side 2 and it’s still getting better My ears are getting tuned in to this luxury sound and it’s like my turntable, amp, room, sofa, everything, is a brand new thing! The reports of the soundstage developing more dimension, the space between the mixing channels and the closeness of the band to you are all spot on. Just amazing.
But I can’t wait any longer – I’ve got to get the ‘special 2nd box’ contents out. I’ve been waiting for this a long time, it was always the plan to give this it’s first play on the LesBox. So here we go, flicking through the options in my shiny new The Beatles In Mono boxset. Not the nasty ’09 digital effort, but this years all analogue extravaganza. Revolver it is. 3 hours later and I’m still buzzing! This beautiful, inspired, personal gift from Mr Carpenter is beyond words. A revelation has occurred. The new mono albums are a superb piece of work and this little MS23 LesBox has taken them beyond any previous level of aural pleasure.
So, not the most technical of reviews, but nonetheless, a HUGE thank you to Les for designing and sharing this masterpiece. Thank you for re-igniting my DIY enthusiasm, and thank you for putting The Beatles in my room as opposed to just in those speakers. I can’t wait for tomorrow to start all over again.
I've been wondering this for a while now.....
How many LesBoxes are out there?
I don't want to hijack this thread, so I started a new one here:
http://www.diyaudio.com/forums/tubes-valves/262218-how-many-lesbox-units-exist-out-there.html
You can just add yours to the previous post and we will have a running total.
How many LesBoxes are out there?
I don't want to hijack this thread, so I started a new one here:
http://www.diyaudio.com/forums/tubes-valves/262218-how-many-lesbox-units-exist-out-there.html
You can just add yours to the previous post and we will have a running total.
Upgrading my rca interconnects now - nothing extreme, but I'm aware of the importance of capacitance etc. As a general rule for the LesBox, would 1.5m cables at 36 Mohms, inductance at 2.5 micro h and 124 pF over the 1.5 m length be about right for the outputs? (Or indeed the inputs). TT is a Garrard AP76 with an Audio Technica ATN91 cartridge.
Hi all,
So, I have also MS-23B modified according Les's instructions (Thanks, Les!) I wanted to use that great Riaa on my MC-cartridge too, but cart output signal level is only 0,45mV, so Step-Up transformers were needed.
I ordered pair of Link: Lundahl LL1931 step-up transformers. Delivery time was a bit long, but worth to wait.
Here's pic's of my Link: DIY SUT Combination of MC-cart, SUT and MS-23LB sounds just incredible. If you are planning to go for MC-cart, do not hesitate, go for it and get SUT too. Another bang for a buck.
So, I have also MS-23B modified according Les's instructions (Thanks, Les!) I wanted to use that great Riaa on my MC-cartridge too, but cart output signal level is only 0,45mV, so Step-Up transformers were needed.
I ordered pair of Link: Lundahl LL1931 step-up transformers. Delivery time was a bit long, but worth to wait.
Here's pic's of my Link: DIY SUT Combination of MC-cart, SUT and MS-23LB sounds just incredible. If you are planning to go for MC-cart, do not hesitate, go for it and get SUT too. Another bang for a buck.
Hi all,
My name is Stef and I've been reading this post with great interest and I have a small question about mr. Carpenters schematic. I was wondering why the output was taken from the two resistors R10 (1K) and 'RAH' (1M). To me it looks like a voltage-divider and then it would make the output less 'strong'. Is there a reason for it?
Thank you very much in advance, Stef.
My name is Stef and I've been reading this post with great interest and I have a small question about mr. Carpenters schematic. I was wondering why the output was taken from the two resistors R10 (1K) and 'RAH' (1M). To me it looks like a voltage-divider and then it would make the output less 'strong'. Is there a reason for it?
Thank you very much in advance, Stef.
Hi Stef, the 1M resistor is a leak resistor to discharge any voltage that may appear on the output if it is not connected to a load. The 1k is added to improve stability, not absolutely necessary and could be omitted but it was kept as part of the original design. The loss across both resistors is really small, if you assume 1 Volt is feeding the resistors then the voltage at the output connector is 0.999V. Even adding a low load, say 20k Ohms, the voltage will only drop to 0.951V.