Valve amp repairs

Those threads on for the xmas holiday!!

Just out of interest, I note that the Django is offered with either S&B transformers (which I know are a favourite of yours Mr L) but I also see a cheaper version using amphorous core transformers. Is this a much inferior version??

 

FWIW I did consider getting a Django over the MC67, but it was twice the price and had no phono stage. Something to keep in mind for the future perhaps....

 

Ive considered the Basie before now but Im sure T will be recommending the Django

 

Hi,

Yup. Or the Tram. The Basie is IMHO a bit too much a compromise. It has been long in the program (from day one) and while it has received many upgrades and revisions including the Phono Option, it really is a little too limited to warrant recommendation as a serious preamp, it would make for a great experimenters platform though to learn a lot of things....

I would suggest the Cole in either guise and either Django with S&B Transformer (my preference) or Tram (Brians preference) if you want something really outstanding, in terms of performance.

In fact, MY PERSONAL CHOICE in this case would be Cole with S&B TX-103 Stepup and S&B 600 Ohm RIAA Modules and an S&B TX-102 equipped Django. That would be very close to what's playing at home right now....

Add a pair of Billie Monoblocks (either version is fine, I lean towards the 91) and a pair of suitably high efficiency speakers and the results can be very good, as quite a few visitors to casa mia will attest....

I would not say inferior per se.

The Chinese AM Transformers lack the transparence and immediacy of the S&B Parts and impart a darkening to the tonality. Some will like the results as they "ape" traditional Valve (pre)Amplifiers somewhat, other will find the resulting Preamplifier not "passive enough".

Suffice to say that I have at home both the Opera Reference 1.3 passive preamp with the same AM TVC's and a Music First Passive Magnetic Preamp. The Opera gathers dust progressively.

Ciao T

 

Do you mean the Ladyday+ 300B monoblocks?

I'm currently researching 300B/211/845 monoblocks for use with the Ming Da, and these have popped-up on the radar.

They seem to offer good vfm, even in ready-made form.

Given the price, and the fact that they have been designed with DIYers in mind, have any "luxuries" that one would normally find in 300B SET's been discarded along the way?

Would sincerely appreciate any views/comments.

Rgds,
DT

 

I was wondering if its the Ladyday's!

 

Hi,

Ahhm, yes. I coined the name that stuck, but never got really used to it...

No, on the contrary. They include circuit design details and technologies (either optional and/or as standard) which are not found in most "cost no object" commercial designs.

I would cite as examples the WE connection of the output stage, the options to use extensively film capacitors in the signal circuit and power supply, the option to use tent lab heater supplies and the optional use of gridchokes in the standard LD+ (LD+91 cannot use Gridchoke), amorphous output transformer option and so on.

If you load up the LD+ or LD+91 (I'd suggest the 91) with the full options you still have an affordable amplifier but one which offers technology and performance not really found in ANY commercial Amplifier all together, no matter what prices we are talking.

How this translates into sound is another issue. Ask others, I may be too prejudiced as quite a few or the tricks originate with me....

Finally, Brian is working on an Amplifier (kit) using the 300B+ Valve from TJ, which will produce around/over 20W per channel.

BTW if you accept a little less output power for the Amplifier at low frequencies could also be build up an Amplifier for the 300B+ using the LD+ Kit (it was origionally designed with that option in mind). Use the original 6SL7 Mu-Follower driver with Gridchokes and the highest voltage available from the universal PSU Transformer (around 450V +B @ 110mA).

You need to add fixed negative grid bias (easily done, Rupert Rupertson shows it for a Kit1 here: http://www.users.globalnet.co.uk/~valveamp/RupertRobertson.htm ) but otherwise you will be fine. The output transformer limits you to around 15W RMS @ 30Hz, which usually is fine....

Ciao T

 

The 20W sound interesting. I was seriously considering the WAD 300b mono's until their demise (and some regulars advising me that others may be better), this new kit could be just the ticket.

 

OK, thanks 3D - sounds quite tempting. The only lingering doubt in my mind is that weeny 9wpc (I assume this type of SET cries when it sees 4 & 6 ohms?) being able to drive my speakers convincingly.

My Pathos is rated @ 70wpc and is working around 70 on the 100-step attenuator to get the Signums up to healthy, room-filling volume.

I have other speakers that I could use, but they're not quite in the same league (Revolver R16's - 8ohm 90dB).

For this reason the Ming-Da push-pull 300B's are quite high up the list. They produce 25wpc, which should prove much easier to get on with.

I'm honestly not keen on changing my speakers to suit SET's unless I absolutely have to....

DT

 

Why? Use the 4 ohm tapping and all is fine.

Well, 110mA/450V with the (admittedly rather expensive) TJ 300B+ gives easily over 15W with reasonable damping factor and good headroom....

All that said, I don't think the Sonus Fabers are suitable to low/no feedback Valve Amplifiers, powers completely ignored on that. They where designed for meaty solid state Amp's or stuff like the ASL Hurricane KT88 graveyard.

Tethering them to a 300B SE amp is like attaching a horse trailer to a Ferrari. Pointless. Get the Amplifier equivalent of big range rover to hang them off....

Ciao T

 

My experience is the exact opposite of Thorstens.

But then, Ive heard a lot of 3dsonics products and simply not liked them, so we obviously have different taste.. and thats all this hobby is, a matter of personal taste.

I havent heard a better pre-amp than the Basie below £2,000. Better of course meaning more to my taste.

Each to their own.

 

Hmmm, an overpowered, unreliable, bling machine that'll dim the lights when used.....

...sounds like an Audio Analogue Maestro to me

 

Hi

I too can recommend the Django pre amp. Excellent value for money. Top notch stuff.

Well worth looking at.

SCIDB