TNT-Audio Readers' Corner
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March 2010

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6 Music and DAB
Hi Mark
I have to disagree with almost everything you said about 6 Music on DAB. If I were to take that argument to it's logical conclusion then I would have never listened to Radio Luxembourg and the pirate radio stations in the 60s, and would have cheerfully got all my music from the BBC Light Program via a VHF radio. One of the principles that I thought was important in hi-fi was that at the end of the day it is "It's the music that matters". That's why my long cherished hi-fi has had to accommodate average store bought records and CDs, rather than be tailored for "audiophile" recordings. It has also had to cater for a range of music, rather than a particular genre which has made getting it right, particularly from the phono cartridge point of view, a long term challenge (the Dynavector 10x5 has been the first to meet all my needs after 35 years of experimentation). The fact is that I would rather have 6 Music deliver what I want to hear, or didn't realise I wanted to hear, on a DAB radio than some "Bland FM" in highest tip top audio FM. The principle is the same.

That leads me to a second point. Though I prefer to listen to Radio Three on FM than DAB (most of the time), I do not find DAB as awful as some might portray. In fact 6 Music can sound pretty damn good at times from my Pure tuner via HK amp and MA speakers. It sounds good in car too via my built in (aftermarket) car radio. The gap in sound quality between DAB and FM, albeit exaggerated by some, will be narrowed as a more advanced system is phased in. This would have to be a long term project as existing users of DAB have a right to be considered. In the meantime I would rather continue to have the option of a so called "imperfect" BBC 6 Music, which is why I initially added DAB capability, than go back to the poorer choices I had.

Of course you could change tack and request that when migration of national stations from FM starts, that the BBC be allowed to keep a couple of FM networks for the more deserving stations from an audio point of view (at least until a superior digital system is up and running), and that Radio Three and 6 Music be the priorities unless you feel that Radio Two is more important to the music industry.
Back under the covers with Luxy!!!
Tony - E-mail: tony (at) at07.co.uk

MW
Hi Tony
Thanks for getting in touch. I have received very few comments about the BBC6 pieces, all the others saying things like "tell it like it is" and nothing more. I am glad you have written the above. Your last comment says it all.

Listening to BBC6 Music is just like being back under the covers with Luxy. A ix of inane banter and sound quality that included the notorious Radio Luxembourg fade.

We suffered those slings and arrows of outrageous AM because we were teenagers sticking it to the man. We were refusing to accept the dull sterile fodder supplied by the BBC Light Programme. I preferred catching Wolfman Jack on the American Forces Network; I listened most nights on a valve radio from a house clearance sale, connected directly through Koss Stereophones (in glorious AM mono of course) under my bedcovers hearing the likes of American Soul and rock we never heard through the BBC. When BBC Radio 1 started this was still the best source after John Peel finished. We were kids then and the low quality sound of subterfuge was part of our youthful rebellion and statement of identity.

We are now middle aged and sadly we now are the man. I haven't spent half a century acquiring the wherewithal for a house full of great music on LP and CD, and great ways of playing it, to accept that I'm still a child putting up with what the grown condescend to provide. BBC Radio2 is great some nights, BBC6 Music is great some nights and even Sunday Mornings have suddenly improved. We are paying for this public service broadcaster therefore have a right (such is the capitalist system) to demand what we want for our money. The BBC should stop trying to compete with the daytime commercial stations and local radio as we are already paying for that through our daily purchases of advertised products. The BBC should aspire to a qulity agenda in content and delivery. He who pays the piper calls the tune is an ancient expression of audio purchase that should be as true now as it was when it was coined.

BBC Radio 3 gets better DAB bandwidth than the other DAB stations which is why the quality gap is smaller; radio 3 also gets relayed via landlines to the FM transmitters; these landlines carry digital signals whose data rate varies according to competing needs such as simultaneous sporting events on various Radio 5 and local platforms. Until the dumb down daytime edict BBC6 Music managed more consistent content quality, but has always suffered delivery quality equivalent to MP3. My kids listen to everything on MP3 for the same reason we tolerated Luxy and AFN. The money you have obviously spent on your system implies that quality is important to you so do not accept being palmed off with second rate quality. The BBC have bought enough digital bandwidth at their disposal to offer 3 high quality music stations and many more speech stations at much lower rates.

Furthermore, I doubt if FM will ever be switched off as commercial stations had a dash from digital, not the dash to digital anticipated. The best of Radios 1 and 2 plus BBC6 could be merged into one great hi- resolution 24 hour music station sounding like the best of each plus comment reminiscent of the the pages of Melody Maker, NME and Sounds at the height of their powers. Meanwhile a MOR station sounding like daytime Radio 1 and 2 plus daytime BBC6 could be streamed at even lower than BBC6 128kbs compressed for smooooth easier listening. Leave the dynamic range intact for the listeners who care.

Come out from under the covers and fire up the main system!

Happier Listening!
Mark Wheeler

About Zero one Ti48
Dear Sir,
My name is Nikola and I live in Bulgaria. Sometime ago I read your article about the Zero one Ti 48 archiving transport and bought one second hand. Few days after that its hard drive died and I have been trying to contact Zero one but they do not respond to may emails. I know that you do not have the time to take care of every single reader of TNT but I was wondering if you have some kind of contact with anyone form their company... I will appreciate any answer from you and I apologize if my email is inappropriate.
Thanks in advance
Nikola - E-mail: krivorov (at) gmail.com

MW
Hi Nikola,
I am sorry to hear that you have had problems with the Zero One Ti48 that I reviewed so favourably. It remains the best digital sound I have ever obtained in my listening room. However, no sound at all is no good at all. The contact details I provided in the review are the only ones I have.
If you are unable to trace Alvin Heng, the designer and founder of Zero One, I would suggest a good PC custoim builder and repairer would be able to retrieve the contents of your old hard drive (I think there are two hard drives in the Zero One working in tandem) and install them on a new hard drive in the Zero One case. Alvin told me that the hard drive itself was a proprietory item, so you could even fit a much larger modern drive in its place.
Good isolation and the very high quality of the power supply is what makes the sound of the Zero One hard drive so special. The drive itself should make less difference.
Good luck in your efforts to get your Zero One server running again, please let us know how you get on.
Happy listening hopefully!
Mark Wheeler

Gainclones & Class D amps
Hi Nick,
I'm an italian reader of TNT-Audio. I've already wrote a mail to Mr. Lucio Cadeddu and he already answered me on Tnt's "rubrica della posta", and he also suggested me to read some of your articles (done!) and in case to contact you if I've again some doubt.
My "audio setup" is made by a Nad C520 cd player, a Nad C320 Amp, Monitor Audio REF 700PMC, TNT-FFRC speaker cable, a DIY signal cable and TNT-Merlino power cable.
I've also upgraded the C520 replacing all the power filter caps with Panasonic FM, I've changed the OpAmp with BB OPA2134, changed in and out caps with Wima MKP 10uF+0.1uF, and the rectifier bridge with 4 Schottky Fast diodes.
I usually to listen rock, rock progessive, some funk and jazz music, in a 40 square meter room (with some furniture).
Now I'm thinking to change the amp...I've already own a heavily modded Sonic Impact T-amp: I found it very nice on higher freq, the soundstage, the dynamics, the "space" between instrument is really better than the Nad...but I found the Nad more "emotional", especially when I start to turn up the volume, and I think I prefer its warmer sound...Maybe it is just the lack of power of the Tamp that cannot drive correctly the MonitorAudio's. My idea was to buy a Tripath based amp kit, with more power than the Tamp (also Lucio suggested me to look for a Virtue.One: more power, better quality...) or to build a Gainclone with LM3886 and (after reading Decibel Dungeon) with a Discrete Buffer.
I've seen that you've got a couple of Gainclones, and you've also reviewed a couple od class D amps...Maybe you can give me an extra opinion to take a better choice...
Also I've seen a lot of projects on DecibelDungeon. I was really interested in the LM3886 inverting configuration that you've posted on your site, with the discrete NPN-type buffer and the PSU with snub filtering. I've some question about the project.
If I use the buffer + gc where do you think is better to put volume control? Between the source and the buffer, or between the buffer and the amp? And in this case should I remove the 47K-100K res from Amp-In to ground?
I would like also to have an advice on input cap: I'm thinking to use Solen Fast (not too much expansive, but they seem good) instead of Auricaps (too expansive, maybe I can change them in the future) or BlackGates (simply out of production :( ). Any idea?
Can I use the same PSU for buffer and amp, or is better to use a separare transf.+regulator for buffer, and another one for the Gainclone amp? And how much current does the buffer drain?
Last: when you say "trafo 2x30V 250VAC" you mean that each secondary should be rated 250Vac or is this the total ammunt for the trafo?
Thank you in advantage for your help Nick...I'm sorry for my poor english... :(
Regards
Andrea - E-mail: andrea.pzo (at) tiscali.it

NW
Hi Andrea,
For an amp upgrade, I would strongly suggest the Virtue class-T amps that have more power than the smaller 12v type. Virtue have just released the new version of their Virtue.ONE amp. I can't tell you how they will sound with your speakers but perhaps you could ask for more advice on the Virtue forum at http://www.audiocircle.com/index.php?board=152.0
As regards the Gainclone with discrete buffer, you could try the volume control either before or after the buffer. That simple buffer does have some DC on the input so using something like a stepped attenuator will cause a small click. You could add a cap to the input of course but that is another one in the signal path and you lose some of the transparency that simple buffer gives you.
I'm not sure about removing the resistor to ground in the amp if you put the pot immediately before it. I suggest asking on the chip amp forum at DIYAudio. http://www.diyaudio.com/forums/chip-amps/
Input caps are a personal choice according to how you like the sound, and how much you want to pay. FWIW, I currently prefer the Obligato PIO caps in the copper jackets.
I don't recommend using the same supply for the buffer and amp because the amp will modulate the supply, and the more 'delicate' buffer will suffer. The current required for the transistor buffer is negligible so you will only require a small transformer.
The transformer that I recommend has twin secondary 30 volt windings and an input rating of 230 volts. Please read the power supply page at DD: http://myweb.tiscali.co.uk/nuukspot/decdun/gainclone_psu.html
To make sure you fully understand power supplies - we don't want to lose any TNT readers just yet! ;-)
Regards,
Nick Whetstone

CD player under 400$
Dear TNT-Audio,
first of all, let me thank you for the service that your site provides to all of us lunatics whose lives are enriched by the interplay of electronic and sonic vibrations.
Due to reasons of economy, my system consists of venerable equipment (twenty, thirty, and even forty years old). Excluding my current cd player, I don't think I could do better unless I spend astronomical sums well beyond my possibilities. So...my question is: what would you think would be the most musical (don't ask me to define the word, since I trust your taste) cd player I could purchase for around USD 400, new or used? Best regards,
Roberto - E-mail: rpicciotto2004 (at) yahoo.com

LC
Dear Roberto,
if you're looking for a multiplayer, able to play almost any digital format available today, look no further than the Oppo DV980H or DV983H, if still available in your Country. Otherwise have a look at the entry-level CD players from NAD (C515BEE) and Cambridge Audio (Azur 340C). Have a look at the second-hand market as well, looking for some Rotel or Rega CD player of few years ago.
Hope this helped,
Lucio Cadeddu

Choosing amplification
Dear Sir, I came across your site and I think you are doing a good service for audiophiles wherever they are. I go back before Audio Amateur. I tried to get on your reader forum but I seem to be stuck. You should have a record of me because I got your robot to e-mail me back. However I can't access your forum. Many of your readers like glass audio. That is also my preference.
The problem is that they act like electric heaters and they are power pigs. I never did think that high power amps was the answer. Matched properly, a system need not be more than 50 watts, if that. My main desire is to tap the expertise of your readers so I can decide what I want. Any help would be appreciated.
P.S. I know how to solder.
Sincerely,
Alfred - E-mail: alfbonke (at) hotmail.com

LC
Dear Alfred,
our forum is set up in a way that I have to manually approve each and any subscription request. This way we can avoid spammers. You should be in, right now.
As for amps, if you are seriously concerned about power consumption and heat build-up, try a Class D amplifier! There are several DIY kits out there that use Tripath chips, for example. We have reviewed quite a few of these. They're easy to build, good sounding and work with 90% of power efficiency. They also run extremely cold and you can choose the right power to suit your needs.
Hope this helped,
Lucio Cadeddu

CAT5 cables
I am building Cat 5 cables for my active quad amped (+sub amp) home stereo all horn system. I believe as the frequencies go up the need for heavy gauge wires is unnecessary, but have not been able to find any info concerning this. All runs will be about 3 meters. Would you be kind enough to help? If it matters capacitance wise the UB, mid and tweeter are powered by SET tube amps.
My uneducated guess is:

Thanks,
Zene - E-mail: zene (at) comcast.net

LC
Dear Zene,
you're right that heavy gauge wire isn't strictly necessary. Actually, it is seldom necessary. Hence, use the cross-sections you have decided, I'm pretty sure they will work well on your system. Just pay some attention to capacitance, eventually measure it after each cable is finished. SET amps might dislike high capacitance cables.
Hope this helped,
Lucio Cadeddu

Listening room
Hello Lucio,
I am back again though you may recollect since you receive thousands of emails. I have written to you couple of time asking about speakers and subwoofers but this time it is about listening room.
The current setup is as follows.

I am planning to have a dedicated listening room of 11(W)X14(L)X11(H). I would not like to keep any furniture in this room so, to dampen the reflections, will it be a good idea to carpet all the surfaces (floor, side-walls, ceiling) in the room? Please share your thoughts on this.
Thanks,
GopalJee - E-mail: gopaljee.nigam (at) bankofamerica.com

LC
Dear GopalJee,
it is NOT a good idea to use an empty room for audio purposes. Actually, it is one of the worst things you can do to your system! Why do audiophiles believe a dedicated room for HiFi has to be just an empty room with a stereo system and a chair is something that I'll never fully understand. Adding carpets everywhere would not be a solution either. You'd need a careful and precisely-tuned acoustic treatment of the room and that should include tube traps, absorbers, diffusers etc. It will be easier and less expensive to add furniture instead :-)
Moreover, my opinion is that the listening environment is relevant to audio enjoyment. How can an empty room be a good and relaxing place to stay in? I'd find it rather sad and depressing.
Hope this helped,
Lucio Cadeddu

Promitheus TVC
Hi Arvind,
Hope you are doing fine. I received my TVC and I am exited about the music it makes. I guess for me it it time to upgrade. I remember you telling me once that Class A is they way to go. I think you mentioned about the Cayin amp. I recently came across a great set of NEW monoblocks from Monarchy - http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1256608799&/Monarchy-se-100-delux-mk2. There is a "special" buy-1-get-1-free going on. I was thinking of going for these amps. What do you think of Monarchy as a company and these amps?
Thanks,
Milind - E-mail: milindpai (at) gmail.com

AK
Hello again Milind,
I am not personally familiar with these, but have heard many good things about them. I have to admit I have been curious about reviewing these for a while but have not found the time yet.
Happy listening,
Arvind Kohli

CD player tweaking
Hi, I am going to tweak my Marantz CD player starting with the clock. You don't state the voltage for the polystyrene film foil caps. I purchased a couple of ROHM Axial Poystyrene film foil caps, .01uF/630v. Will these work ok?
Thank you,
Bob - E-mail: bobbyv2 (at) comcast.net

LC
Dear Bob,
I can't remember the original values of those caps but, as a rule of thumb, you should just replace them with better caps of the same value (pF) and voltage (V). 630 Volts seems a very high operating voltage (is it 63.0 perhaps?), check the original ones and act accordingly. The pF values have to be as close as possible to the original (or greater if working on the PSU) and so the voltages. A higher operating voltage cap shouldn't harm anything. You are just adding a more robust component that can withstand higher voltages if required.
Happy tweaking,
Lucio Cadeddu

Power supplies (again)
Hi Lucio, for the reader asking about power supplies for his phono preamp: these can be found at www.autocostruire.com or a mouser catalog which contains several pages of linear and switching power supplies here in the USA.
Best regards,
Richard - E-mail: babydock (at) bellsouth.net

LC
Dear Richard,
thanks for the feedback. Incidentally, Autocostruire.com is located in Italy, although it sells worldwide, perhaps it would be wiser to purchase something closer to where you live. Indeed, consider that mains voltage in Italy is 230 volts and not 110 like in the US. Then there are customs fees to pay etc. Moreover, as far as I know, the ZetaGi PSU's work at 220/230 Volts only. I'm pretty sure something similar can be found for less, directly in the US :-)
Happy listening,
Lucio Cadeddu

MDF cabinet blues
Hi Mark,
At the end of your DIY loudspeakers series - Part II, you mentioned that you would explain how to rescue mdf cabinets and give them a new lease of life in a future article. I would be grateful if you could some give advice in this area. As the owner of a pair of floorstanding Tannoy R3's I am only too aware of the mdf cloud in the midrange in an a pair of speakers which have an otherwise great retro sound.
It is nothing short of an audio disaster that the vast majority of hi-fi lovers have to listen to music via mdf speaker cabinets. It is only the very high end stuff that uses non-mdf cabinets. Funnily enough quite a few midi systems (Sony etc) use chipboard for their speakers.
As a result the sound if nothing else is a little quicker and more natural. I strongly suspect that mdf is the reason why a lot of the pre-mdf speakers such as the LS3/5a fetch good prices. Hopefully future tastes will go back to midrange purity and musicality. Better bass is always welcome, but not at the expense of the midrange.
Thanks
Jas - E-mail: jaswant4 (at) hotmail.com

MW
Hi Jas
How correct you are on all counts.
MDF is only used because it is cheap to manufacture accurately. It was initially sold as an advantage by manufacturers but that is just one of those situations where "Hell hath no fury like a vested interest masquerading as a moral principle". MDF sucks because it sucks the life out of music and frankly for the same thickness is inferior in the bass compared with void free birch plywood as well as midrange. It is thickness, bracing and damping that dictate which part of the audio band is favoured. The most colouration free cabinets I have ever heard or made were 25mm baltic birch ply with no more than 150mm between braces (hence no part of any panel is more than 75mm from a perpendicular brace). Accurate bass and rhythm are the foundations of music and solid panels contribute to this.

You are also correct in reminding me that I have not written the article about rescuing MDF cabinets, partly because I got so behind with projects that I had to pay a joiner to undertake the work but have not completed testing. The work is not complicated to undertake and with most cabinets should take less than a weekend.

I will get around to it soon.

Happier listening when they're done!
Mark Wheeler

DIY CAT5 cables
I just wanted to say thanks for the page on making a budget wire that sounds good. In case you wanted to add to your page, I included some pictures of my own. I also made an interconnect using the same method, and it rocks.
Regards,
Eric - E-mail: ericthemormon (at) gmail.com

[CAT5 cables]
[CAT5 cables]
[CAT5 cables]
[CAT5 cables]

LC
Dear Eric,
thanks for the nice pics and the extremely positive feedback! I'm just a bit worried about the capacitance of that interconnect made with braided and twisted CAT5 cables. Have you measured it?
Happy listening!

Concordant excelsior pre-amp
Hi Mark
Thanks for your previous reply, I was directed to your site by Andrew Puffer who used to help Doug along with others, demo his range of amps and pre amps.
I was always impressed with Dougs demos at the now defunct Chesterfield shows. I've quickly learnt that Dougs creations come in many variations as he was always striving to improve things. My Excelsior has a GE 5751 in the 3rd position of the moving magnet stage, and a GE 5965 in the PSU. I was advised by Andrew that the last pre's featured a ECC83 in place of the GE 5751 and a ECC88 in the PSU. Replacing the GE 5751 with a Mullard ECC83 made an amazing improvement. Replacing the GE5965 requires a rewire of the base to accomodate the ECC88, something I might try later.
Best wishes,
John - E-mail: john.rushby1 (at) btinternet.com

MW
Hi John
I am surprised that subbing another ECC83 for the 5731 made an improvement, although it may be the fact it's a Mullard NOS that does it. The ECC83 is higher gain but less of a driver. Doug stuck with the GE5965 as long as he could in final RIAA phono position, even when he switched to using Golden Dragons, a switch he made merely because it was becoming madly time consuming to match the sound and performance of the different brands of NOS he had in stacks of hundreds of boxes in the little room above his front door.
I have a late revalved personally by Doug Excelsior in my system as we speak and it has a 1960s GE5963 in the central socket and Golden Dragons ECC83 elsewhere.
I would not change the valve in the power supply for any other type. Doug used TV deflector valves in this position for very good reason and they are still popular with fanatical Japanese and American tube-heads instead of more common rectifier diodes like the EZ80. The valve that should be there is a Westinghouse 6CG7, taller than typical B9a audio valves but that is common among old TV valves. The silk screened nomenclature looks like 6CGT which would means a 6C in a glass tube.
You cannot try any of the other TV damper tubes in the 6C family because they come on 5, 7 8 and 12 pin bases!

The 6CG7 tolerates anode (plate) voltages of 330V at 600mA. It was designed to be a controlled warm up deflector - remember how long it took televisions to warm up? Valves like this were the reason. It is electrically equivalent to the ubiquitous audio octal 6SN7, hence it ought to work well in the second stage of the RIAA phono section of the pre-amp.
However the 6CG8 is an unusual two section valve with a triode and a pentode under the glass; Glass Audio published a fascinating active crossover design featuring this valve. Completely irrelevant but I'm a sucker for such trivia.

Try the GE5965 in the central socket of the pre-amp and use TV defector tubes in the power supply. Paying contemporary NOS prices for popular valves like Mullard ECC83 and ECC88 is less fun than sourcing interesting lesser known equivalents. Often there is so much headroom in the ratings in our audio application that many types will survive.
Andrew was probably one of the many I met at Doug's house or at Chesterfield; one day we should all have a reunion.
Happy tube-rolling,
Mark Wheeler

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