TNT-Audio Readers' Corner
Monthly section devoted to your letters, positive and negative feedback about everything related to Audio and HiFi.

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March 2004

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Dynaudio's matching
After many years of living in Brooklyn and listening to a tiny sony portable set, I'm determined to invest in a hi-fi system to play in my 11x23 rugless living room. All the pieces will sit within an elevated cabinet, so the speakers will be bookshelfs. I've become smitten with Dynaudio 52se's. On account of space constraints, I'm planning on an integrated solid state amp with a phono stage. I've been searching for one under $1200 that will make the Dyn's sound good at modest volumes as my ears can't take loud music now that I've reached the old age of 38.
I prefer to purchase a new piece, as I'm deterred by the risks of buying used expensive equipment from strangers off the internet, but I just found out my brother in Binghamton lives down the road from a store that specializes in selling and repairing classic Mcintosh.

Please suggest a few options for a new integrated amp with phono stage to mate with the Dynaudio's. And I'd also be grateful to get your perspective/advice on taking the classic Mcintosh route instead.
And congratulations and many thanks for your work on this brilliant, accesible and friendly website.
Thanks again,
James - E-mail: brooklynolmec (at)

Hi James,
You've got quite a few choices in your price range. Arcam offers two Diva's under $1200. Both have phono stages. The Roksan Kandy is a nice integrated and well within your budget. Rega even offers some really nice integrated's. The Classic Mac should mate well also. The list goes on and on.
Ultimately, your choice will come down to your ears and the features you want. I'd suggest opening the phone book and visiting the many audio salons in the NYC and Jersey area.
Best regards,
Scott Faller

Revox B126 and B226 - where's the difference?
Hi Lucio,
After reading your review of the Revox B226 and hearing B226 Signature by myself I'm on the way to purchase one of those Cd players. Thank you very much!!!!!!!!!!!!!!!!!!!
Yesterday I opened this B226 Signature and I found that inside there is TDA 1541 (not even TDA 1541 A) . I expected TDA 1541 1S. Is it normal? Should it be signed on somehow that it is TDA 1541 1S?
I find nearby the B126 at the reasonable price. What is the difference between B126 and B226? I saw on the tnt forum that you answered similar question, but it is in Italian. Unfortunately I'm not able to read it :((((((((((((
In the Revox Service (Switzerland) they sell them both almost at the same price. What D/A is in B126? I think they change transport as well am I right?
Thank you very much once again and warm greetings from cold Poland
Andrzej - E-mail: horyza (at)

Dear Andrzej,
you didn't read my article carefully. Indeed, cutting and pasting from it you get what follows:

"You can find a B226 Signature, more or less a B226 with a classy all-black finish and a B226S, the most "audiophile" of all, featuring the famous TDA 1541 S1 (Silver Crown) DAC. This DAC, sometimes, can be found even on standard B226's."
This means the B226 Signature is internally identical to the B226 standard. The "mean machine" is the B226S, instead, with Silver Crown 1541 DAC.
Moreover, there shouldn't be sonic differences between a standard B226 and the B126. The latter had just less features. Soundwise, they should perform very close.
If the price for the B226 is the same, buy that one. Normally the B126's sell for less (as they were cheaper).
Hope this helped,
Lucio Cadeddu

TNT Stubby
Just wanted to send you my thanks for posting your website on the TNT Stubby speaker stands. A mate and I built a set stands each using your instruction set with only 3 deviations, not bad for guys that rarely read directions for anything. We chose to router 1/8 inch deep circle for the pipe to fit in and we chose to use 4" diameter pipe. We also chose to clear coat the painted pipe for a glossy look.

My NAD C350, NAD 520i, and my Paradigm Monitors thank you. Every time I fire up the system, I get a little smile on my face from listening pleasure. And my bank account is very happy :-)
Sidney - E-mail: sidney.anderson (at)

Hiya Sidney,
Glad we could be of some help :-)
The routed circle really is the proper way to build these but many people don't have the means to do it. I imagine they look pretty sharp! Like we keep saying, high end doesn't have to cost huge dollars. Enjoy and check back often for more cool DIY projects.
Scott Faller

Tubes dilemma
Dear TNT,
Please let me know betewen all the 845 single end tubes amp and the 833 A witch is the more musical and if you can tell me differences of musical performance of both. Did you already listen GU 50 amp? It will very useful if you can answer because you are always right and you have listened to all the tubes of the world.
With best regards,
Pierre - E-mail: p.ghaliounghi (at)

Hi Pierre,
The question you ask is difficult, if not almost impossible to answer. Let me explain what I mean. Each of the amps you mention (845, 50, and 833) all (can) have different circuit designs that utilize driver tubes.The 50 tube can be powered by a single driver tube. I've got a 50 amp in house that is driven by a 6SN7. It also can be driven by several other small signal tubes. The 845 is the same. You can drive it with a 6SN7, 6AU5 or any number of other tubes.
The 833 you mention is a different animal completely. This isn't a triode as the 50 and 845 are. This is a beam tube. If the amp you are looking at is the WAVAC, this thing is driven first by a WE437 (6c45pi), then into a KT88 (in wired in triode) then that drives the 833. This is a completely different circuit design than the 845 or 50. As you are aware, different driver tubes sound....different.
Different circuits sound....different. Unfortunately, there is no common, commercially available circuit design that utilizes all three of these output tubes (that I'm aware of). This makes a direct comparison of the tubes a near impossibility.
Taking all of the sound of the individual tubes out of the equation, if you are actually considering the WAVAC 833 as your next amp (at $60,000+/pair), I'm not sure any 845 or 50 designs will ever meet your expectations.
Scott Faller

SAT cables resource
Dear TNT,
I stumbled across the following page today: I notice that CT100 satellite cable is mentioned. TNT readers might be interested to know that we can supply this and similar cable (H109) in cut lengths of up to 20 metres or on 100 metre reels. In fact I think the foam dielectric WF100 would be better still.
We may also be able to supply the little black plastic boxes mentioned as we stock something similar. If you are interested, I'll check on the actual dimensions of the type we stock.
For cable see We also stock a few connectors - gold-plated spades etc. and specialised wire: see Best Wishes,
Martin - E-mail: genman1 (at)

Dear Martin,
thanks for the precious information!
Lucio Cadeddu

Cartridge standards
Greetings from the American Deep South!
I've read your Zero 100 articles with great interest because I am the (?) proud owner of a Zero 100 and I want to get it up and running again. Everything about your article is very clear and concise except for the business concerning the stylus/cartridge. How can I buy a Grado cartridge with the assurance that it will fit into the tone arm?
The cartridge that is now installed is a Shure cartridge dating from the 70's. Will any of the Grado cartridges fit into the same Garrard slot? Will the connections on the back of the Grado cartridge accept those now on the turntable?
As you may surmise from the level of my questions, I'm a neophyte to the turntable world and don't know from beans about them.
Please, can you provide any direction?
Thank you,
Bill Key - E-mail: Bill.Key (at)

Dear Bill,
since this is a very frequently asked question I've decided to answer to it publicly. Almost any turntable in the World uses a standard 2-bolts headshell so that ANY standard cartridge will fit perfectly. Apart from the now discontinued TP4 no-bolts (plug and play) standard or some Ortofon Concorde-like standard ANY 2-bolts cart will be OK for any 2-bolts headshell. The rear electrical connections follow a standard color code. So buy any cart you like, Grado, Shure, Goldring...anything you prefer or find as a better deal. Your Garrard will accept it.
Hope this helped,
Lucio Cadeddu

TNT U-Byte 2 DIY cables
Dear David,
I don't know whether anyone still builds this cable in the UK - I am in the process of doing so and think I have found a good coax cable to start with.
This has a solid copper central conductor, foam dielectric and a copper shield, a 54% coverage (i.e. loose) copper braid and a mylar sheath inside a PVC jacket. Listening results will have to wait completion of my construction project, but I was mightily impressed by the low price of 30 pence per meter (!). If anyone is interested, the link for this cable is
Would the addition of the mylar sheath offset the lower dielectric properties of the PVC I wonder, or is it only there for strength and as a moisture barrier?
It would be great to find a coax cable that had a useable sheath - and so did not need replacement by heatshrink. I found some with different plastics in the form of 'plenum cable' - but with braiding still in place I guessed this would not help much as I would still need to remove both. Finally on coax though, I wonder if Thorsten's comments on stranded wire are still relevant where the stranded braid is in intimate contact with the copper foil shield. If you are still in contact, I would be interested in his thoughts.
Other comments - I had great problems finding any KYNAR heatshrink sleeving in lengths above 1.2 meters, and the prices were also very high. I could not find any made from 'KYP' - Thorsten's other recommendation. I finally went with polyolefin sleeving from RS-Components, but with new plastics emerging since the article was written in 1988, I would be interested if better and cost-effective alternatives are now emerging. Wire-wrap wire seemed to draw a blank on the search engines, so I am using solid-core (copper) bell wire with a PVC sheath.
For the record, I presently use a single run of Kimber 8TC to my B&W N805 speakers. I agree with Thorsten's comments on the cost-effectiveness of Kimber, although I think he was talking about thinner 4TC. I am proposing to bi-wire with the UBYTE 2 on the tweeter section as Kimber themselves suggest 8TC is best for woofers.
Thanks for a great service. If anyone produces UBYTE 3, I will be interested to hear.
Best Regards,
Peter Walker

Dear Peter,
Thanks for this very interesting account of your experience of building TNT UBYTE 2 speaker cable. I'm not in touch with Thorsten (he still receives his e-mail, though). I hope it might also be possible to include your comments as a P.S. to the account of how to build this cable, as a way of keeping the site up to date.
Your link to a UK supplier will be particularly helpful to UK and European readers.
Thanks for your kind feedback,
David Holgate

MAD Ultra 4A + NAD C370 combo, any good ??
Hi, Scott. Having read your review on MAD Ultra 4A Tubed Preamp I am so interested in getting it for partnering with my NAD C370 (120w, SS, amp gain of 29dB); wonder if it would be a good match ?? Please tell me also whether there would be an audible hum with this combo?
Any tubes upgrade that you would like to suggest? ( I like a softer, warmer, full-bodied sounding with a good Bass) I will be using such combo with my Tube-drive -Ah4000 CDP (Amperex7308x2,+Upsampling).
Your opinion and suggestions is highly appreciated and thanks in advance
Simon - E-mail: simon.leemd (at)

Hi Simon,
After reading your likes in sound presentation, I think the MAD Ultra will be a very nice match for your system. You shouldn't have any hum issues at all. When I had the MAD here for review, it was dead quiet. As for tube upgrades, there really aren't many to consider. I'm not aware of any big name tubes like Mullard or Telefunkin in the 12SN7 (though I didn't really look either). If you are looking to do some tube rolling, let me suggest that you have Dr. Lloyd wire the MAD for 6SN7's. You'll find loads of cool NOS and current stock tubes to choose from. It seems Lloyd is also offering an upgraded version of the MAD. It uses AuriCaps (our fav's) and Black Gates.
I imagine that refines the sound of the Ultra 4 quite a bit. Based on what you want in your sound, I'd say go for the standard version first. You'll have to decide on the 6 or 12 volt tubes though :-)
If you think you'd like a bit more detail after listeing to it, Dr. Lloyd (or a local tech) can always upgrade the coupling and bypass caps for you for not much expense.
After all is said and done, I think you'll really like the sound of your system. They should all make a really nice combination. Then you just need a turntable so the phono stage doesn't go to waste :-)
Have fun,
Scott Faller

TNT Stubby stands
Hello Scott,
I am building your stand, with some addition's. A small additional tube true the main one for cable routing, spikes on top for the speakers, and a bigger main tube: 125 mm don't know what that's in inches.
I'll let you know how they sound when their finished. Thanks for your site, and all ideas on it!
Bart Koop - E-mail: b.koop (at)

Hiya Bart,
Glad you found your way to our site :-)
Your tweaks to the Stubby sound interesting. Be sure to let us know how you like them.
Best Regards,
Scott Faller

Dear mister Richard George,
to start with the question: can you help me finding the wiring diagram or schematics of the Dynaco ST-70 Series II? I have an ST-70 which is fine. It was no problem finding the info on this one. Then I bought the Series II but I cannot find any information on this. When I bought it some resistors appeared to have been removed and changed by a former owner. I want to put in the original values and that is why I would like to have the wiring diagram.
I have read the article of Harvey Kader on both Dynaco's but my e-mail to him came back. So if you or a colleague of yours can help me with this one I would be very grateful.
Why would it be so difficult for the Series II and so easy for the original ST-70 ?
Thank you very much and kind regards,
Charles Leijdekkers

Hello, Mr. Leijdekkers,
I was hoping I had the schematic in my Dynaco files, but I do not. I have placed a few inquiries to see if I can find it. So far, two have answered that they do not, but if I find it, to please send them a copy, too.
As to you last question, several contributing factors come to mind as to why the ST70 schematics are easy to find, and the ST70 II schematics are not:

  1. The original ST70 had been in production from 1959 into the 1980s, during the peak of valve-kit and DIY valve amplifiers. Literally millions of ST70s were made.
  2. The ST70 II was made at the very end in the 1990s, and in relatively small quantities.
  3. The original ST70 was designed and sold as a kit, with instructions and schematics. It was also available as a finished product, but huge numbers were sold as kits. Even the finished product included schematics in the owner's manual.
  4. The ST70 II was designed and built with proprietary circuitry, as a finished unit - never in kit form. I have never seen a manual for it, much less a schematic.
  5. The original ST70 was designed by David Hafler and built by Dynaco. Dynaco made its name and fortune providing reasonably high-quality products at bargain prices. Note - the output transformer in the original ST70, the A470, was excellent. They may have skimped on connectors and passive components, but the trannies were first class.
  6. The ST70 II was supposedly built by Sound Valves for Dynaco, then marketed by Dynaco.
There are probably more things I can't think of right now. I tried my link for Sound Valves, but it didn't work. It could be that Sound Valves is now out of business. I know they were in business just a few years ago because I have one of their driver upgrade boards for my ST70 sitting in a box waiting for me to have the time to use it.
Richard George

Super site --- here's a suggestion
Dear Lucio,
I read your plans for 2004 and you mention reviews of old equipment. I wonder would it be a good idea to have such reviews in a separate section but also to have lots of relevant links. I am thinking of e.g. Quad speakers [which is what I use] and I have found lots of sites on rebuilding them. I believe there are also sites devoted to rebuilding/improving/changing Naim products.
Just a thought.
I really enjoy the site ....
James Hamilton - E-mail: j.hamilton (at)

Dear James,
perhaps when we'll have enough reviews of vintage gear we can create a separate section/directory for them. Until then, they'll be stored in a subsection called "Oldies but Goldies". If you've read my articles on earlier Naim gear you should have noticed I included several relevant links to amateur sites and forum of Naimees. As for mods on 'em, stay tuned because something will be published soon :-)
As for Quad, I admit I have not enough experience on them but certainly our Werner (Ogiers) has. We can ask him to write down one or two articles on old ESL's and 63s, for example. In the meanwhile, if have questions about Quads, contact him anytime.
Incidentally, I'm going to review the recent Ken Kessler's book on the history of Quad electronics. Really a "must have" item.
Lucio Cadeddu

NAD 3045
I've read your review about the NAD 3020 and was wondering if you had any knowledge of nad 3045, which I presume came out a little later. Although I maninly bought it mainly for cosmetic reasons- (it had a nice teak cabinet and had analogue meters) which I've never seen before, I'm disappointed in the sound quality.
As per your advice I'm letting it warm up a bit. In the mean time I'm wondering if you have any knowledge of this amp and what kind of sound I should be expecting from it. How does it compare to 3020?
Also the meter doesn't seem to be working- is this fixable?
thanks, dean, a huge fan of TNT
Dean - E-mail: dkimny (at)

Dear Dean,
I've never compared the 3020 to the 3045 but all the 3xxx series amps from NAD do sound reasonably good. Your unit, perhaps because of excessive wear/age, may need a recapping, that is new capacitors in the power supply section. At the same time, some deoxidizing may be useful (selectors and volume pot). While you're there, have a look at the VU meters, perhaps it is just a problem of rust/oxide build-up.
Anyway, while the 3020 was a real champion, its brothers never had the same success. I wouldn't expect too much from the 3045.
Hope this helped,
Lucio Cadeddu

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