Valve amp repairs

Seem to have a bit of a problem with one of my Audion mono s !

Anyone know of a valve amp repair man in NW London??

Used to have the odd repair done by a chap called Theo down Alevandra Palace way but can't find his phone no

Cheers
Jeff

 

jeff I know some good people in Milton Keynes. If thats close enough PM me.

 

I know a man in Fulham. PM if interested.

 

Hi

While I don't neccesary specialise in repairs (mods
/design instead), I'm pretty close (N9) and happy to help, if it's not too much work, plus I know Audion stuff pretty well.

PM me if interested....

Ciao T

 

Now there's an offer.

 

hmmm, must make a mental note of this.

Would be nice to have a 3DSonic'd TubeBox ;-)

DT

 

Hi,

Sorry, but I'm refusing to work on THAT thing....

Why not learn to solder and build my "Valve El Cheapo" Phonostage (a tricked out and upgraded version of this design is available as Kit and assembled from www.diyhifisupply.com BTW as the "Cole"), which can be build for beer money (well, at London Beer Prices anyway). And DIY is SO satisfying....

You might find that you could even fit the actual Phonostage into a stripped out "TubeBox" and build a hulking big external PSU Box....

Ciao T

 

Lol - didn't think it would "float your boat". Not exactly at the bleeding edge of tube amp design, is it?

 

Just a quick big thanks to Thorsten for kindly sparing some valuable time of his for my amp. A very interesting - and educational time for me I must say. Fascinating to see a schematic for the amp being drawn up before my eyes and a few quick mods yielding the results as predicted !

:respect:

Cheers
Jeff

 

Jeff,

No worries, nice meeting you.

I am still weary the patient will develop more trouble (I hate intermittent faults), but we will see....

Let me know how you like the new sound when you had some time.

The Vino was a rather nice tipple too, thank you.

Ciao T

 

Excellent !

 

Incidentally, I have sold my Pro-ject TubeBox and put the proceeds towards a (horror of horrors) Ming-Da pre-amp - the MC67-HA ( http://www.pureaudio.net/preamps/ming-mc67ha.shtml ).

It has a 100 Ohm MC phono stage which uses 6N3 tubes for amplification. Its fed by a 6N6 rectified power supply (which also feeds the line stage). MC signal to noise ratio is 81dB. The line stage uses five 6922's and has a "high level" 5v output.

OK, so it looks a bit naff, what with all the tacky gold trim, but internal build looks fine from what I've seen. A bargain for £380 IMO.

Now of course, the temptation is to buy the matching monoblocks, which again, are insane VFM. The guy I bought the MC67-HA from is offering the 300B's for £850, 805's for £750 and the 845's for £775. This is for airmal delivery so ground shipping would save £100 but take two months.

Very tempting - particularly the 805 based model

DT

 

Hi,

Let us know how it works/sounds. Last I heard about a Ming Da Phonostage was not particulary encouraging, I hope you have more luck.

Ciao T

 

Well, for the money (and the fact its integrated), I'm certainly not expecting miracles. Anyway, its a sort of stop-gap before upgrading the entire analogue front-end.

DT

 

DT,

Other people on zg and pink fish have had different results with ming da phono stages - often prefering them to more expensive alternatives.

I'm sure you will let your own ears be the judge.

 

Hi,

The problems I heard about had mostly to do with noise levels.

Ciao T

 

I had a Ming Da MC767 which is a phono stage only. I was dissapointed both with the level of noise, too much hiss, and with the clarity of the output signal. Far too much musical detail was being lost. After some posts on another forum I built the valve EL Cheapo deisgn of Thorstens, it was my first dip into valve DIY and so I needed quite a bit of help. The Valve El Cheapo FAR outperforms the Ming Da, bigger soundstage, much lower noise level and fantastic transparency and is still in use. I didn't know there was a " tricked out and upgraded" version of it, I may have to look into that.

Kev

 

Where are the details for the valve el cheapo?

 

Ouch - sounds bad Kev. I nearly went for the MC767 myself! The MC67 is their new "reference" pre-amp (which considering it costs $550 is quite ridiculous - its supposed to drive the MC300-845 which is a rather nice pair of monoblocks).

It has an MM/MC stage bolted-on, which is a bonus IMO. I'm guessing the architecture of the two phono stages is very similar (unless they've learned from MC767 and made some improvements?).

But, like I said, its more of a stop-gap and I'm not expecting anything other than an adequate performance from the MC stage.

DT

 

Hi,

A little history first...

A while ago Real Hi-Fi distributed a certain chinese brand. They had a number of interresting products, but their preamp line in the higher price range sounded okay but no more on the line-stage (derived from the Matisse Circuitry from what I could tell) and pretty limited sonically on the Phonostage (Dynaco PAS derived).

I ended up doing a re-design (standard CJ PV-10 style line stage and the Phonostage that was to become el cheapo) which was intended to become the UK version, for a number of reasons the distribution of the brand was stopped by Real Hi-Fi. The original design plans ended up at the factory but where never implemented there. With some time lapsed and seemingly no commercial application I released the design into the public domain, it was extensively written up and discussed on DIYAudio.com, mainly in these two threads:

http://www.diyaudio.com/forums/showthread.php?postid=335624#post335624

http://www.diyaudio.com/forums/showthread.php?s=&threadid=54534

I appreciate that these are very long threads, but it is recommended to read them entierly and carefully.

Anyway, this design was also picked by DIY HiFisupply's Brian Cherry and early builds sounded pretty good, so I worked a little with Brian to tweak up the cicuit to get the last few jucy drops of music out of the design, making it however less simple in the process.

The result is the DIYHiFisupply "Cole" Phonostage, with the addition of some MC Stepup transformers and this makes a cracking and affordable phonostage, add the "Django" passive preamp and you have an exceptional Preamp system for fairly little money.

BTW, the "LCR Cole" is a very different design (even if it appears superficially identical) and has more in common with the Wavac Phonostage than with the "El Cheapo".

Ciao T