That example applies to speakers that have a system mechanical Q of 3 )on a quick scan). Those are out the window if you have speakers with a different mechanical Q. If for instance you have speakers with a mechanical Q of 0.5->0.7 or so (rare in today's world) the optimum damping is zero.
Amps & speakers have to be thot of as a system!
dave
Hi, Davepaul again after a few months break--- I'm not sure I'm doing this right, but--- I asked about a "hum/earth like" problem I was having [pages 12/13] and Jpeg kindly replied so I thought it only curtious to update. I tried the amp (MC 10 L) one last time befor starting swapping tubes round and the problem has never reoccured again, even after many hours of use!! Strange but true. New question -- has any one fitted the Screen Grid Stoppers/Current Limiters as suggested by Les Carpenter in his/her article " A Look at the Yaqin MC 10L" ?It has been suggested to me that these are a good safety idea.
I firmly believe the choice of 6N1 is very much down to personal taste. I have tried Svetlana 6N1P, they were an improvement but not a patch on the first quad set I bought. These were date stamped 1982 and instead of 6N1P, they were marked in Russian characters as 6H1N-EB with an additional OTK1 marking. These are the sweetest so far to my ears but I think everyone who has tried swapping out the originals will agree that you will certainly hear a difference.
BTW From feedback I have been receiving, it may not be long before I re-wire the heaters and fit 12AT7's
BTW From feedback I have been receiving, it may not be long before I re-wire the heaters and fit 12AT7's
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They sound just wonderful with Magenepan MMG's. So natural it is hard to fault. My wife (who knows nothing about audio) loves the sound and a friend also commented. I managed to get a pair of near new maggies and immediately went to find a tube amp. The Yaqin suited them so well...
Hi Jkorten, I stripped down an MC-10T in search of variations between it and the the MC-10L.Only the resistors feeding the Blue LED's had been changed to make them a little brighter. The other change was of course the heater wiring for the 12AT7's but all other component values remained the same. I have been so busy building and repairing audio stuff that my planned conversion has been sat on the back burner but I do want to start sometime. I have the 12AT7's and the components necessary to do a 60V heater lift. Les
Finally getting round to upgrading the caps. Took a look inside and I could not find them, never mind replace them ! Les says they are C104 + C105.
- Can someone point them out to me on a photo pls ?
and
- Recommend suitable caps pls. Make and value would be helpful
PS: the Yaqin logo is lit by the light falling into the casing and not from the power still being connected !
Oh and a happy New Year
- Can someone point them out to me on a photo pls ?
and
- Recommend suitable caps pls. Make and value would be helpful
PS: the Yaqin logo is lit by the light falling into the casing and not from the power still being connected !
Oh and a happy New Year
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I changed mine for these:-
ANSAR Polypropylene Axial Audio Capacitor Tolerance 5% 220nF (0.22uF) 630V.
Available from:-
Cricklewood Electronics - CCTV. CCTV Equipment. CCTV Systems. Digital CCTV Cameras
I achieved better results by replacing the front end valves.
By the way: Check your voltages as I note that your amp has a 220V Mains Transformer!
ANSAR Polypropylene Axial Audio Capacitor Tolerance 5% 220nF (0.22uF) 630V.
Available from:-
Cricklewood Electronics - CCTV. CCTV Equipment. CCTV Systems. Digital CCTV Cameras
I achieved better results by replacing the front end valves.
By the way: Check your voltages as I note that your amp has a 220V Mains Transformer!
Thanks Les, those blue things did catch my eye but couldn't read any values on them.
So I need 4x 100nf.
Do the 220nf's have no affect on the sound ?
The Ansar's are rather too basic an upgrade to make much of a difference I imagine.
How about these ? :
ClarityCap ESA range of capacitors home page
or Mundorf or Jensen but don't know which range to choose from.
Me too rolled the x4 front valves which took the glare away that the stock tubes had.
Soon as I lifted that lid that big 220 hit home hard !
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I tend to agree with you about the caps even though the description of them made it look worthwhile trying. I did not want to go too high like 470nF as sometimes it can have a negative effect and cause problems, so I was being a bit cautious and decided to just double them. It was more of an experiment really, if there was a Bass improvement it was very subtle. The wrapping on your mains tranny looks a little discoloured in the centre so it must be getting quite hot, just keep an eye on it. I have measured my MC10-L across the audio bandwidth and found it very flat, there are no peaks or troughs at the lower end, which is what I would expect the amp to do. If more Bass is required it could be the speakers, their placement or the need to fit an EQ ahead of the amp. I find this a particular problem with phono amp stages, the ones I have made hug the RIAA curve but folks want more Bass! That is not the job of the phono amp, for my latest design using op-amps, I added a small EQ stage within the buffer and it made a tremendous difference.
I will order some of those ClarityCaps ESA for starters. Shall I do a direct replacement on values ? Also they do them in different voltages 250 and 630Vdc ?
I ran a pair of speakers for an hour last year on the wrong ohms setting, noticed it got rather hot which was what alerted me !