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

You are here > Home > Staff & Contacts > Letters of the month

February 2007

Please take a moment to review the How to use the Readers' Corner manual

Going active
Hi,
I read an article by Mark Wheeler on active / passive speakers and was wondering if Mark or one of his colleagues would be able to spare a moment to comment on my problem.
I have an Arcam Alpha set up - alpha 9 CD player, alpha 10 integrated amp, alpha 10P power amp. All pretty good mid-range kit and top of the Arcam range when I bought it several years back.
I also have a pair of AE120 floorstanding speakers. These are 3 way speakers - 3 pairs of posts at the back, 1 treble, 1 mid and 1 bass.
I've tried all permutations of set up as follows - using 3 runs of cable.
Tri-wire the speakers into the 2 amps:

Bi-wire the speakers into the 2 amps: Whatever I try I always feel there's something more to be done. I'm using Silver Anniversary speaker cable and Chord Chameleon interconnects. I either get a forward bass presentation, or a flattish mid-range. The system seems not to sparkle. I've also tried re-positioning the speakers, putting sponges in the rear ports etc etc.
I had a listen to a Linn system with active speaker set up last year - out of my price bracket at the moment - but I'm keen to get somewhere close.
Is there anything else that you think I could do to improve my lot with the current system - is it worth buying another power amp to tri-amp the speakers, or would I be better swapping the speakers for a pair with 2 drive inputs instead of 3? Alternatively, sell up and go for the true active solution?
On paper what should the best wiring / amp config be with the kit that I've got?
Any comment gratefully received.
Cheers,
Ian - E-mail: ian1harding (at) btinternet.com

LC
Dear Ian,
I'm not a big fan of passive multi-amping. The real benefits of multi-amping can be obtained only by means of active filtering (i.e. electronic crossover BEFORE power amps). This means the speakers shouldn't have passive crossovers. That said, if I were you, I'd sell the Arcam gear (integrated and power-amp) to buy a SINGLE integrated amp of higher quality. Then I'd try to tri-wire the speakers to the new amp. Which amp, you may ask. Well, that depends on your budget and on how much you can get from your existing amps.
If you want "sparkle", dynamics and superb detail retrieving I'd suggest to have a listen to the NuForce IA-7 integrated amplifier, for example. Or to a NAD S-300 and a Krell KAV-300i, in the second-hand market. I'm pretty sure your speakers will start to shine.
Keep me updated!
Lucio Cadeddu

Going active - II
Hi Mark - Enjoyed your acticle on TNT on Active Speakers!
Have just gone 'Active' myself.
I purchased an electronic crossover from Marchand Electronics (XM9 2 way stereo). My speakers are Wilmslow Audio Classique,a 2 way design with a Volt bass/mid and a ribbon tweeter.
The CD player is a modified Njoe Tjoeb with upsampling and the amps are Behringer A500 (two stereo). All cables are from Chevin Audio with a Russ Andrews super Purifier and a home made conditioner.
I asked both Volt and Visaton before proceeding and they both were positive with the 'active' approach. I am very positive with the results Active has added to my system. Without going into Hi-Fi speak, the sound hangs together in a way it just didn't before and all types of music have benefitted from this approach.
I haven't had any problems with Bass as you mentioned could happen so generally a very good result for the cash outlay. Mike - E-mail: mikebooth (at) talktalk.net

MW
Hi Mike
I'm really glad you wrote about your active speaker success, especially because my first active project used the Wilmslow Decca-Volt cabinet, but I substituted the Focal 10N501 bass-mid driver because I thought it's midrange character and dispersion would better match that of the Decca London Ribbon's 90° horn. That Visa looks like an interesting unit..I may try a pair myself.
I would like to review the Marchland crossovers for TNT-audio as they have been dedicated to the cause for years. Given that you're happy to use Behringer amplifiers, what made you decide the Marchland crossover would be worthwhile above Behringer's own range of active crossovers? Still much cheaper than a killer amp to drive passive crossovers.
Wilmslow passive crossovers always specify good bass inductors so there will be less than 1ohm added series resistance affecting the bass alignment, hence your experience that the active version did not differ too much. Happy listening,
Mark Wheeler

Trusting the reviewers
Hi guys,
first of all a big 'thank you' for your outstanding website. Having just checked for some used units on ebay, it was quiet obvious how popular your site is ,as -for example- every other seller of the hk 680 points to your review. Well done. I recently relocated to south africa and am currently building up a system, since the stereo-bug has bitten again. I've got the hk 680, a yamaha cdx 993 is on it's way (currently ca. 250.- euro each on ebay) and the speaker kit for the north creek rhythm just arrived 10 days ago.
I build them very quickly and must say the risk of ordering an unheard speaker was hugely rewarded. I'm not a reviewer, but to me they are the best speakers I've heard so far. I noticed this company is not mentioned anywhere on your site, so I would like to draw your attention to this manufacturer (this guy made upgrade crossovers for b&w speakers). Unfourtunately they don't sell kits anymore, but they still produce interesting speakers, namley a new advanced ribbon speaker, the Metro. Their websites are northcreekmusic.com / NorthAcoustics.com / AdvancedRibbonTechnologies.com
I really would love to hear what you think about them. Maybe a review ??
You also gave me the means to do more diy, and I'm quiet happy for now with the Star speaker cable and will make some interconnects soon. Now I know cables can make an audible difference. I'd also like to build me a valve amp, and so I was looking for the Edison 60 Amplifier Kit, which I couldn't find anywhere on offer. Is it discontinued ? If so, is there anything else out there?
Now another thing I'd like to mention, is how important and helpful your reviews are to some people. Living in South Africa (and quiet a few other countries have the same problems) it is practically impossible to listen to most of the better units. Factors like vast distances, limited availability as well as the policies of dealers prohibit this. Also not everybody is a seasoned reviewer......so I prefer - and I'm sure many others do so as well - to select my system 'with a little help from my friends', you know, the guys from...TNT.
Thanks again P.S.: having read so many reviews on your site, following idea came to my mind. what about a test of entry level systems, one consisting of used units (like my hk 680 and yamaha cdx 993) ,the other of new units somewhere close in price class. it would be intruiging to see which way one gets the best sound for the money...
Paul - E-mail: paulhannas (at) gmail.com

LC
Dear Paul,
first of all thanks for your kind words. I'm afraid I can't say much on North Creek speakers as I've never auditioned them. The market is full of interesting products but unfortunately we don't have the time to listen to everything. This applies also to the P.S. part of your kind letter: it would be fun to compare old and new gear (and we did it, several times) but we are hard pressed to review new things that appear extremely interesting.
I also understand your point about "trusting the reviewers" but it is an attitude we have always tried to fight: we reviewers have our own tastes and preferences, it is hard to understand how a component sounds like by simply reading a review. Reviews might serve as simple "hints" and nothing more than that.
Finally, for the tube amplifier kit, we have reviewed quite a few of these, simply browse our amp reviews section. Since your system isn't "ready" yet, take all the time your need to familiarize with it before adding another "variable" (the tube amp). You might even discover you don't need tubes :-)
Happy listening!
Lucio Cadeddu

NAD 3020
Just read your notes on the NAD 3020. Could you please answer the question: is there a problem with my amp when turning it on it produces a short burst of low frequency hum which lasts around 5 secs then decays to silence. I have only had the amp for a few weeks which was given to me in very poor condition but I have managed to bring it back to fair condition.
Many thanks,
Derek - E-mail: D.P.Beesley (at) open.ac.uk

LC
Dear Derek,
a short "BUMP" or "THUMP" when turning on the amp has to be considered natural. If the bass frequency noise lasts for 5 seconds...then it's not 100% normal. I'm afraid the power supply caps are almost gone. Replacing those with fresh ones will also improve the sound. Choose good quality caps with the very same specs. Eventually, install (slightly) bigger ones, bigger in terms of uF, I mean.
Also, try spraying some good contact dexosidizer on contacts, input selectors and volume pot.
Hope this helped somehow,
Lucio Cadeddu

Vinyl...
Dear Arvind,
I read with interest your thoughts about the perceived differences between vinyl and numeric musical formats.
I would like to -modestly- give you some explanations about this. Believe me,I'm no expert about maths, but this explanation surely has something to do with maths. Namely, The Shannon/Nyquist theorem. This theorem, roughly translated in usual words, tells you can obtain the original image of a quantized signal, with an excellent accuracy, with a quantization frequency which is twice the frequency of the original signal, provided you make adequate calculations, defined by the theorem.
This is the point. Historically, when cd was created, no computer in the world could possibly make these calculations at the right pace - I mean, reproducing the music as fast as the cd was played - except perhaps some of the first criogenically-freezed computers used for weather prediction.
So, the analogic curve - consequently, the voltage sent by the cd player to the preamplifier - was rounded, not properly calculated. Lack of precision, problems of perceived pitch, and sensation of unnaturalness of the music resulted. Now, more than 25 years after the beginnings of the cd, things are a bit :-) better. But no cd player really does the adequate calculation, the result is just mathematically better rounded. So the original fullness of the original signal is not properly re-created. I think the adequate process would be quite easy for today's computers - I mean, an usual PC no more than two or three years old - if somebody would know how, and could care about, making an adequate program. But, as you told, CD almost killed by vinyl, and maybe MP3 will push away CD.
Another problem related with quantization is: it is usually said, as I put it before, that you need twice the frequency of the original signal to obtain the adequate precision. But if you don't use properly the Shannon/Nyquist theorem, ten times would be more adequate. So instead of 44.1 kHz, 441 would be needed. :-(
Same kind of problems with the precision of sampling - in the present situation of digital replay without good signal treatment, 16 bits for one sample - i mean, to express thesound pressure at the moment the sample is made - (again, cd standard) are not enough. I suppose 28 would be adequate.
As you can see, even the new formats can't be completely convincing, even with 24 bits, 192 kHz quantization.
Just some words about vinyl : no quantization, the diamond stylus retrieves information from a continuous signal groove. And if you can hear the surface noise, don't forget there is is information under the surface noise - much information you can hear, ad contribute to re-create the musicalperformance. With cd, 90 dB under the maximum level, lies the zero information floor.
Sowewhere between 50 - 60 dB at best under the maximum level - 0 dB - music becomes very hard and strange. So, the precision of a CD player decreases - or, distorsion increases - as the signal is weaker. This is a very unnatural behaviour, because in the real world, sound distorsion - creation of more harmonics - is greater with the loudness, this is a physiolgical data of our ears and our perception of sound. Again lack of natural.
So, nothing really surprising if you like vinyl. Please, feel free to ask me to make things clearer about all this - or to give you more details, or, if I can, make my rather poor English easier to understand.
Best audiophile/musical regards,
Eric - E-mail: brandizi (at) linuxmail.org

AK
Hello Eric,
thanks for your kind words and sharing your thoughts on why vinyl sounds better than digital formats. I cannot claim enough knowledge to agree or disagree with what you have said. Judging by your technical/analytical bent, you might be interested in the following article by Christine Tham.
http://www.audioholics.com/techtips/specsformats/LPsvsCDsDynamics.php
I can certainly say that my ears generally concur with her conclusions, based on my experiences with other gear and albums.
Regards,
Arvind Kohli

NOS or Oversampling?
Dear Mark<,br> I was very interested by your Consonance Opera 120 Linear review. As far as I know Consonance seem to be the only CD builders that sell two different models, the CD120, using Oversampling and filters; and the CD120, Linear, using NOS and Jfet analogue filtering. There seems to be this same pairing with the Ref 2,2 MkII and the Ref 2,2 Linear.
I am basically an analogue person http://www.theanalogdept.com/anthony_hind.htm, but I do need to change my CD player. This is an old Sony 16 x 2 player. I have found this superior to most CD players I have heard recently, including the DCS Elgar which I did not like, and various Wadias.
I borrowed an Esound E-5 and hated it. It was as though the oversampling was adding some sort of false detail, and falsely widening and deepening the Sound stage.
I have not as yet listened to a modern NOS player. I heard an early Consonance, but I think it was upsampling. Do you think it could be worth my looking at these Consonance NOS machines (120 or Ref 2,2). As an analogue person I don't really believe digital can approach analogue, so I am not ready to spend a fortune.
I also noted that on 6Moons (http://www.sixmoons.com/audioreviews/consonancelinear/reference_2.html) Srajan Ebaen preferred the NOS Ref Linear to the Oversampling Droplet, and he said it had something of the SET quality about it. There are a few other machines that some people have mentioned to me: the Cairn Fog (which in spite of its upsampling was judged by Lucio Cadeddu also as SET-like. These are being sold greatly reduced at around 750 as opposed to 1750 $/Euro, as they are being replaced by the Fog3), the Unison Unico (that has a glass lens to the laser), and the Lector.
I would be grateful for your thoughts on this subject.
Regards,
Anthony - E-mail: anthony.hind (at) noos.fr

MW
Dear Anthony,
Ah, the great upsampling, oversamplng or non-oversampling debate!
I do not think the answer lies in one technology being inherently superior to the others. Because each implementation is different, and we're all familiar by now with so-called perfect digital-domain chips having almost as much individual character as a pick-up cartridge, that it is impossible to know which technology is inherently superior because there are all these other variables in our listening equations.
I loved the CD120linear, as I made clear in my review. If valves & vinyl are your chosen poison, I suspect it would be a good choice.
If your analogue taste runs to an all-Linn front end (for example, Sondek LP12, Ittock LVII, Klyde) or Roksan or other Flat-earth flava, then I think other players might suit you better, such as those from Naim, or the Avondale Audio rebuilt models I reviewed and still use alongside my Shanling, at about the same price as the Consonance. The Avondale designer, Les Wolstenholme, also eschews up-and-over-sampling, regarding it as one of the fundamental cd problems. I'd love to hear what he could do with a Consonance CD120linear, as I suspect his power-supply expertise could bring the CD120linear's rhythm and pace up to better-than-Naim.
If high-end grandiosity is your preference, you might like the upscale sound of the Vacuum State Electronics versions of the big Sony players. My colleague Geoff was impressed by Consonance Droplet too. My impression is that implementation often has more influence on ultimate sound quality that the underlying technology (I loathed the original oversampling Arcam, but loved the NOS Avondale built on the same transport and chipset foundations).
I do think it would be worth seeking out the Consonance CD120linear to audition, and perhaps a Naim, as a complete contrast and then decide which character better matches your analogue tastes and system.
Happy listening!
Mark Wheeler

Glass & HiFi
Dear Lucio and TNT team,
this week Maarten van Casteren reported on the HiFi News 2006 Show and I noted from the photos that so many of the exhibitors had their equipment on metal and thin glass equipment stands. I don't understand this when many of your reviewers and masses of other hifi gurus castigate metal and glass stands as having such bad acoustic properties such as vibration transference, acoustic reflections and other more esoteric problems.
On the other hand I noticed in Stereophile's review of the CEDIA 2006 Show that most American equipment producers had their gear on wooden or very thick glass shelves. Are American and English producers/exhibitors on a different wavelength or do they care less about glossy appearance and more about the acoustic properties of what their equipment should be placed on in the USA?
I also read with great interest last June Arvind Kohl's interview with Pierre Sprey of Mapleshade records where Pierre talked at length of the importance of not only placing musical instruments on wooden stands when recording but also of placing your speakers and equipment on similar wooden stands to get the best reproduction of the recorded music.
And TNT's own DIY equipment stand proposes wooden shelves. Surely this is not just because it is cheaper and easier for the DIY enthusiast to make shelves of wood rather than glass?
Best regards,
Michael - E-mail: michael.shanahan (at) telia.com

LC
Dear Michael
wood is a cheap and very good sounding option when it comes to HiFi stands and racks, indeed. And wood DIYing is very easy. That said, there are excellent stands and racks with glass shelves and you might be surprised to know how many good turntables use glass platters! This means that glass isn't bad per se. It may surprise you that I currently use two HiFi racks with tempered glass shelves and tubular steel structures :-)
Even glass can sound good, especially if you avoid to use spikes and direct coupling devices. It is better (and safer) to use shock absorbing (read: damping) feet instead.
Hope this added some extra confusion :-)
Lucio Cadeddu

Low cost HiFi

Woodelf - E-mail: bfranchuk (at) jetnet.ab.ca

LC
Dear Woodelf (?)
frankly I'm not 100% sure I got you right. You seem to complain that we consider "low cost" an item that is in the 1000 CAN $ price range. It all depends on what the market has to offer, I'm afraid. DIY is an option but it isn't - AND IT CAN'T BE - for everyone. HiFi is expen$ive, yes, I can't agree more on this. This is the reason why we try to focus our attention on components that offer a reasonable Q/P ratio.
Stay tuned,
Lucio Cadeddu

Unusual use for a T-Amp
I am using this amp in an unconventional way. I have this hooked up to an electric guitar processor, and use it with monitor speakers and guitar cabinets, depending on the situation. This amp works very well with electric and bass guitar processors, and trust me, I believe the final result is a very realistic (as processors go) sound from a set of guitar cabinets.
Works well with music also, but that has been stated. In all, a very cheap amplifier to use in conjunction with a guitar processor.
Bradley - E-mail: Bradley.Morgan (at) carle.com

LC
Dear Bradley,
thanks for the feedback. I guess the output power of the T-Amp is too low to decently amplify a guitar, unless you use extremely high-sensitivity drivers. Anyway, you seem to be satisfied with it....so enjoy! :-)
Lucio Cadeddu

[ 01/2000 | 02/2000 | 03/2000 | 04/2000 | 05/2000 | 06/2000 | 08/2000 | 09/2000 | 10/2000 | 11/2000 | 12/2000 | 01/2001 | 02/2001 | 03/2001 | 04/2001 | 05/2001 | 06/2001 | 07/2001 | 08/2001 | 09/2001 | 10/2001 | 11/2001 | 12/2001 | 01/2002 | 02/2002 | 03/2002 | 04/2002 | 05/2002 | 06/2002 | 07/2002 | 09/2002 | 10/2002 | 11/2002 | 12/2002 | 01/2003 | 02/2003 | 03/2003 | 04/2003 | 05/2003 | 06/2003 | 07/2003 | 09/2003 | 10/2003 | 11/2003 | 12/2003 | 1/2004 | 2/2004 | 3/2004 | 4/2004 | 5/2004 | 6/2004 | 7/2004 | 9/2004 | 10/2004 | 11/2004 | 12/2004 | 1/2005 | 2/2005 | 3/2005 | 4/2005 | 5/2005 | 6/2005 | 7/2005 | 9/2005 | 10/2005 | 11/2005 | 12/2005 | 1/2006 | 2/2006 | 3/2006 | 4/2006 | 5/2006 | 6/2006 | 7/2006 | 9/2006 | 10/2006 | 11/2006 | 12/2006 | 1/2007 ]

[ Home | Staff & Contacts | DIY & Tweaks | Listening tests | HiFi Playground | Music & Books ]