30 June, 2012

Letter from Robin in Taipei

Letter from Robin in Taipei
Editor: As you know, our friend Robin the Scott, the man who revived the Tascam R2R and stunned us with its sound, now lives in Taipei. Their magnificent residence sits atop beautiful Yangmingshan (a national park) and commands a panoramic view (click pics to enlarge). I received this email from him and took the liberty of publishing it

Robin wrote:

"...The transformation of our listening room on the 3rd floor here in Danshui is now more or less complete. See attached pics: it was formerly green (the colour of the bare boards we put up), but recently we had the walls and ceiling painted lime white (a big improvement.) 

There's about 15 cm of soundproofing material in place throughout the walls and ceiling, and all the windows are double-glazed -- but of course that just stops the noise getting out and disturbing the neighbours. The next phase will be to treat the internal room acoustics, using sound absorption panels. As you can imagine, one gets quite a lot of echo and bass standing waves in such a large listening space as this! I already have lots of fibre-glass boards lying around -- left over from the earlier construction work -- so it's just a question of finding the time to do this second part of the 3rd floor conversion. Should be lots of fun, though I will need to avoid over-damping the room's natural liveliness.

More fun here: http://www.drytech.com.tw/tape -- a Taipei company that I bought several dehumidifier cabinets to hold my R2R tapes in did an interview and photo session with me, to market their cabinets (I got a discount from them in return). as you'll see from the pics, I now have three R2R tape recorders. (One can't have too much of a good thing, etc.)

12 June, 2012

Review: Croft Micro 25 Basic Preamplifier

Review: Croft Micro 25 Basic Preamplifier, What a Bargain!

Official Website

Glenn Croft, most respected UK tube guru/auteur, amongst the last of a dying breed, has certainly been around. For the longest time, he has been making excellent tube products at bargain prices. Perhaps he is as famous for the unadorned looks of his creations as his legendary OTL amps (which I had the fortune of hearing at my friend mda's place; but apparently and unfortunately Croft doesn't make them any more). Some years ago, I almost bought his Vitale preamplifier, but it took my trip to the UK this year for me to finally acquire a Croft product.

Croft Micro series Preamplifers Croft has been using the term "Micro" for his preamplifiers on and off for a long time. The latest is the Micro 25 series, I suppose an anniversary designation. His current amplifiers are simply designated Series 7, a continuation of previous efforts. I learned about the current products through reviews of the Micro 25 Preamplifier and Series 7 Amplifier (Tone, TAS).

click pic to enlarge.

Micro 25 Basic
It must be emphasized that the product under discussion is the cheapest Basic version, not the regular version reviewed in the links above.

Built The box is OK, but packing material is quite a joke (I have no idea if export versions are different) - there is no foam or cardboard, instead consisting of crumpled paper (apparently compaction is achieved by stepping-on them, as shoe marks are evident). No manual is provided. The case is very basic, but slim and solid. Lettering is a bit smeared (don't know if it is better in the non-Basic version). The knobs are cheap plastic, but you can easily upgrade them for little money so that your unit looks like the non-Basic version(s). I have no problem with the utilitarian RCA connectors and toggle switches.

Power Supply Only 4 screws hold the cover. Once inside, I have even more admiration for the built. In the power supply, unusually there are two transformers (which are the same and appear in series). I wrote Croft and was informed one was for B+ and the other heater supply. At this price point, I applaud the presence of transistors for power regulation.

Preamp section is well isolated from the power supply and is truly compact. I have no problem with the basic volume pot and selector. Like all Croft preamps. the entire preamp section is hard wired through a basic terminal strip (which may raise eyebrows), with the bigger caps anchored to the chassis. Resistor and caps used are basic but of good quality. This unusual method of construction for sure guarantees very short signal paths, but may prove troublesome should modification is desired or service needed. I cannot decipher what cables are used inside. My unit comes with 2x JJ ECC83 for the phono section and a Sovtek 12AX7WB for the line section. Since the website says 5965 for the linestage, and since 5965 is not exactly the same as 12AX7 I am not sure what is the import on sound, I wrote Croft on this. I received this reply: "...later Basics like yours can only use the ECC83 in the line stage - the 5965 has a higher heater current. The ECC81 and 5751 are other options for the line stage....". Now, that settles it - the info on the website has not been updated.

The separate volume controls for the two channels enable one to adjust for balance. The mute switch is useful for turn-on and -off, and also for phono users.

Caution! I must caution you on connection to the amplifier. Here, the Preamp Output is simply marked "Out". Adjacent to it is a "Line Out" which turns out to be what we would call "Tape Out". I mistook the latter for the preamp out and got full volume. Fortunately I was able to immediately shut down my amp so no damage was sustained. Also, as this basic model has no protective relay or auto-mute at turn-on, if you intend to use it with a transistor power amplifier you must wait a couple of minutes for the preamp to stabilize before playing music, or risk damaging your amp and speakers (tube preamps sometimes output DC at turn-on).

Sound-Round 1 in NYC
I first listened to the Croft in NYC, with the help of a step-up transformer (although the transformers look like they could easily be re-wired to 110V, I didn't do it).

Driven by Wavac MD-811A, sound through my reference highly sensitive YL 4-way horns was a bit rough at first, but settled quickly. The sound was forward, quite dramatic and palpable, equally adept through both the line and phono sections. However, a bit of amelioration/smoothing with old-stock tubes was needed, as the forward natures of both the preamp and the loudspeakers could sometimes be too much of a good thing. Swapping in RCA 12AX7s did the trick for me.

In that system, the Croft proved to be highly capable. Even with 100 db sensitivity, the preamp was commendably very quiet even when phono was used. Although with large orchestral material it did not match the Shindo Monbrison dynamically, it acquitted itself quite well, with particularly impressively clean bass. With jazz and pop material, the sheer presence was quite enjoyable. Although it did not quite yield the ultimate details and at times I could detect the thinnest veiling, somehow it gives life to instruments like few preamps can - they simply sound more real. That is quite an accomplishment. 

Sound-Round 2 in HK
Back in HK, I paired the Croft with another Wavac amp, the MD-300B. Sound through the Tannoy Canterbury though was quite a different thing. With the same tubes inside, the preamp sounded just a little too soft on attacks. Some of this has to do with tube rolling. I left the strong-sounding stock tubes in NYC, and did I wish I have them with me now! Some of this I think also has to do with the gain structure. In NYC, turning the volume pot just a wee bit got plenty loud. With the less sensitive Tannoy I had to crank it up some more, and as is sometimes the case with one-tube linestages (it partly depends on the design) the volume pot gets progressively insensitive. I swapped in some other tubes and got improved results. Also, in terms of the line section, the Croft benefits from stronger-sounding digital sources - low output and refined types may not suit. As for the phono section, it is excellent but not quite the equal of others that have better power supply.

What is interesting is that, with the Tannoy, and perhaps due to run-in, the Croft acquired a refinement that had escaped me at the start. The faithful rendition of instrumental timber is still there, but now more subtle sonic textures can be heard - indeed it can be quite refined with tube rolling, if that is what you are after.

Some musical examples. When I substituted the re-issue Marantz 7c everything moved backwards. In the Beethoven violin sonata from Argerich's Lugano 2011 set, both the violin and piano became more recessed into the soundstage; the piano grew more full bodied and the violin was sweeter. But I have to confess the sense of a live event was better conveyed by the Croft, even if the tones of both the violin and piano were leaner. Playing the vinyl of Ellington's Blues in Orbit, it was obvious the Marantz 7c had more oomph, though the Croft held up valiantly.

The Croft Micro 25 Basic turns out to be a little enigmatic, and that is one of the things I like about it. For a pittance it lets you go straight to the heart of the performance. It is also quite responsive to tube rolling. While its performance may differ a little from system to system, it is that rare thing, a bargain with a huge personality. The price is incredible - for the same money you cannot even buy a Chinese preamp with phono. If you are interested, think also of the higher models, the Micro 25 and the 25R; I wonder how much improvement they would bring?

Buying from the UK
Since Croft has no dealer in HK, those interested would have to buy from the UK. I bought mine from Divine Audio. Buying in the UK saved me shipping, but I had to pay the VAT and get the refund back later when I left the UK. The government red tape took quite a while, but I am pleased to report that I got the VAT back and salesperson Tim Chorlton was a tremendous person to deal with, even answering emails when off work! If you buy from HK, you don't have to pay VAT in the first place, and Divine Audio knows how it works. There are other dealers who ship out of the country, but I do recommend Divine. Check for prices as there has been a recent price increase, not reflected in some dealers' websites.

07 June, 2012

Talk Vinyl: Two Top Values

Talk Vinyl: Two Top Values
Talk DIY: MC Step-Up Transformer
Brief Review: CineMag 3440A SUT 
Brief Review: Denon DL-301MkII

Revised July 10, 2016 (Budgie SUT mentioned as 3440AH alternative)

As promised, brief looks at two items that really surprised, and delighted me! Both are phenomenal values that unambiguously within the first notes earned my greatest admirations. They are sure to go into my Best Buy 2012 list, if I remember by then that is!

Gears Used for this Evaluation:
Turntable: Thorens TD-124 Mk I with SME 3009S2i (and Denon DL-304)
Preamplifier: Shindo Monbrison
Amp: Wavac MB-811A
Loudspeakers: YL Acoustics 4-way horns

pic of unit that is like mine

CineMag 3440A Step-Up Transformer (SUT)
I first learned of the CineMag CMQEE-3440A SUT (used and likely popularized by Bob's Devices) from Art Dudley's review in Stereophile. I first wanted to just buy the  transformers and build one myself. They are available on Ebay (currently $180 per pair), and if you are into DIY, that is the way to go.

I got caught up by other things and promptly forgot about them. But some time later, by chance, I came across a used unit on Audiogon and bought it for a reasonable sum. The seller claimed it was an older version of Bob's Devices, but I have some doubts after checking pics available on the internet. While the enclosure is in hammer tone, there is no marking, the inputs and outputs are on the opposite long sides and there is only one toggle switch on top for gain (no ground defeat). Although I am not entirely sure of its provenance (I think I shall write to Bob after publishing this post for him to read), I think it is closer to what was sold on Audio Asylum. I can assure you though that the unit uses the genuine CineMag CMQEE-3440A (red logo) transformers and that it works great.

I can also assure you my listening results are valid as they almost completely match Art Dudley's descriptions, doubly so as Art Dudley and I both use Shindo preamplifiers. His  Shindo Masseto is, as far as I could judge from the pics and descriptions of components, very much like a beefed-up version of my Monbrison. I am certain the same Lundahl moving coil step-up transformers are used in both units.

As I have said, I got the same results. Fed into the MM stage of the Shindo, the sound is superbly detailed and punchy, bringing life to my Denon DL-304 like nothing before. And yes, it trumped Shindo's built-in Lundahl's. I also briefly compared it to my rare and expensive WE285L and Langevin SUTs; to say the least, the 3440A is their equal, and actually bettered the WE in this application. That says a lot.

Incidentally, Dudley has recently reviewed the more expensive BD CineMag 1131, and the review is worth reading for the story on CineMag's recent developments. I hope one day I could get my hands on one of those.

A concern: BD has gone up quite a bit in price. BD's 3440A version now is almost double the price quoted in Dudley's review, but for its performance can still be counted as good value for those not willing to DIY. The spread between the transformer costs ($180 on Ebay) and BD finished product ($650) is kind of big imho, but I am sure BD makes excellent products and they certainly deserve the credit for putting the CineMag SUT on the map, though I do hope BD shall hold the line on its price. (2016: Note that Bob's has gone upscale and no longer offers the 3440A, instead the 1131 and SKY versions. Also, Parks Audio Budgie uses the CineMag 3340AH, sells for a reasonable sum and has a good reputation. I haven't heard it but would love to.

Denon DL-301 Mk II Moving Coil Cartridge
I have used Denon cartridges for over a decade and am a die-hard fan. Surely there are no greater bargains in the entire analog domain. The Denon DL-103 has always been my go-to cartridge, and the DL-102 is now my mono reference. Numerous friends use the 103R and I also use the DL-304 in NYC. I have always been curious about the 301, now in its Mk II incarnation, as it has a body that resembles the DL-304.

I installed this on the SME3009S2i in lieu of the DL-304, just one day before I left NYC last time, so it is not even close to broken in. But its performance instantly captivated and surprised me.

In the same system, the DL-304 had produced a very detailed and neutral sound that could be a little lean if care is not taken. But the DL-301MkII is very different: it immediately grabbed my attention by its sheer presence, thereby making the DL-304 sound a little clinical by comparison. It is balanced, tuneful, and, like the DL-103, not the last word in details, but it is early on. There are no formal reviews on the internet, but read this review in Audiogon; the author likened it to the long discontinued DL-103D, which I have never heard. Personally, I think its sound is like an amalgamation of the highly detailed DL-304 and the highly musical DL-103, not a bad place to be! Part of this may be attributed to its "healthier" output of 0.4V, as compared to the DL-103's 0.3V, not to mention DL-304's paltry 0.18V.

The DL-301MkII deserves to be better known. It is a much easier cartridge to like than the DL-304 and an even higher output than the ubiquitous DL-103(R). I suspect in actual use it will sound better in many cheap and moderately priced systems than its more famous siblings.

Last but not the least. The retailers usually have this at $329, but if you are willing to wait, consider ordering it from Comet Supply. You shall save substantially. This curious retailer offers steep discount but does not always display Denon products on its website. Call if in doubt. See, they basically collect enough orders for a group buy before action. My DL-301MkII took several months to ship. I have ordered another lot of Denon, which I am sure won't ship any time soon. But the price is worth the wait. While you are at that, seriously consider ordering more than one Denon cartridge; they are that good.

04 June, 2012

Review: Canare L-2T2S and Sommer tricone MkII

Talk Cable: DIY Cables, a Must for any Audiophile
Review: Canare L-2T2S and Sommer tricone MkII interconnect cables

For the longest time, my reference interconnect cables have been the various Gotham cables, and that is unlikely to change at all. However, from time to time, I do try out a few other makes. Before I go into my recent forays, let me say why I think DIY cables is a necessity.

Why DIY Cables? Simple, "Audiophile" cables from audio manufacturers are mostly scams. The most balanced cables I have heard have all been no-frills professional cables. Unfortunately, most are sold as bare cables and termination is required.

Design your own cable? No. Some people assemble their own cables from core conductors and add shielding etc. In my experience, most of these sound unbalanced. There is much to choose from professional cables that self-assembly is a waste of time.

So when I say DIY, it is limited to termination. 十個名牌音響線九個不平衡;十個自作音響線九個不能聼。

RCA connectors I use cheap connectors. My own inclinations on RCA connectors: the connector must be rust-proof, light and made of THIN metal (such as the imitation "Canare" sold in HK). Many expensive boutique connectors, such as WBT, use chunky metal, but they look more impressive more than they sound good. Think about it, why would you want to use an expensive cable composed of many fine strands of conductors, then attach a huge metal chunk at the end to connect to a tiny female RCA connector (usually cheap even on expensive gears, and made from thin metal) on the machine?

Solder The solder must flow easily and quickly. Use sparingly, just enough to do the job and no more. I use standard stuff (I still have the older tinned ones, which I prefer). There are people out there who swear by difficult-to-manage silver and other expensive solder formulas, but I'd urge you not to get anal about it. The whole thing about solder that is like no solder (that is totally transparent) is nonsense. If you believe that, you might as well use solder-less screw-on connectors (but not WBT; use cheap ones, like the very light aluminum ones, the "brand" of which I forgot, available in HK).  

Which cable model? Most professional cable companies make a large number of models. Picking and choosing can be rather bewildering. My philosophy, if you can term it that, is to try out the cheapest model. With the reputable manufacturers, they never disappoint. You can then move up the price point if you wish, but I find the more expensive does not at all equate the better. More conductors, more complex configurations/geometries, more shielding etc may bring about better RF rejection or measurements, but sonically there is no guarantee.

A Note of Caution There are plenty of so-called cable experts out there, who terminate for you for a substantial fee. They claim perfect soldering etc. Some of these people may have the skills, but they also inflate their own significance. You can also develop them on your own to save yourself a lot of money. and have some fun on the way. 除了專業音響工程店外,十個所謂HiFi音響線專賣店十個黑;其它十個賣HiFi線的九個騙。

Illustrated Guide to DIY Cables This profusely illustrated site for how to terminate a cable is simply great. I just discovered it and am happy the author and I have much in common when it comes to cables.

And now brief reviews of two cables.
Canare L-2T2S (official info)
I have always liked Japanese Canare cables. The cables are soft to touch (a good sign) and sound musical. This is unlike Japanese Mogami, which tends to be much leaner. Japanese Softone/ICL equipment comes with cheap Canare cables that sound surprisingly good. This L-2T2S model is very cheap (HK $ 16/m), and available by the foot or in bulk (like here).

This cable has a fully fleshed out midrange and finely balanced sound. It has neither the ultimate attributes nor serious deficiencies. It matches perfectly my Thorens TD-309 turntable. A great starter cable. When I have time, I may compare it to Gotham GAC-2. People who find Mogami too lean can try this out. Who says there is only one "Japanese sound"?!

Sommer tricone MkII (official info)
I have never heard Gotham (old stock or current products) I don't like, but that is not the case for German Sommer. I have heard Sommer cables several times and in general they seem to be lacking somewhat in rhythm and pace. A friend even lent me the very expensive (around US $200) Epilogue. It is not a bad cable, revealing and balanced, but one expects a little more musicality, particularly at the price. The cheapest of the line, the tricone MkII, is no exception, but for the ridiculously low price (HK $12/m) its performance is very good indeed and there is much less to complain about. Overall, I still prefer the Canare L-2T2S.

FYI, I also got a bit of much more expensive Galileo 238 plus (HK $38/m) to try, and shall report later. I am not the only one who suspects the cheaper Sommer models sound better than the more expensive ones.

Incidentally, I noticed that the word "highflex" on my tricone is in italics, whereas that on the website picture is not. I called 雅歌 and was informed that Sommer sometimes changes things without notice.

Where to get Canare and Sommer in HK
Most HK audiophiles get their Sommer and Canare from Apliu street, particularly 雅歌. The staff is very friendly, honest and helpful. They won't recommend anything unless you want them to; no hard sell here. Here are their details:

Acoustic Engineering Co Ltd 雅歌工程有限公司
G/F., 66 Yen Chow St., Sham Shui Po
Telephone: 2729 1022
Fax: 2725 6787
E-mail: acoustic01@biznetvigator.com

However, 雅歌 is only the retailer who gets their supplies from the distributor. For Sommer at least, 雅歌 gets their supply from Palonn 柏龍, who is listed in Sommer's official website as a Hong Kong distributor, although the same website also lists another two dealers for China, and both have HK addresses (one even has a "sommer hk" website). So, it is a little complicated. But unless you plan to buy a roll, Apliu Street and 雅歌 is still your best choice.

03 June, 2012

Talk DIY: Pro's and Con's

Talk DIY: Pro's and Con's

Brief Reviews: Marantz 7c preamplifier
Brief Review: Sun Audio 2A3/300B amps

I started to write a short review on some DIY cables, but the article expanded on its own. Here, I give my views on the role of DIY in audio. They are my honest two cents, but some of these run contrary to popular opinion, so ymmv.

Is DIY in audio the way to go?
In general I have mixed feelings on DIY. Theoretically, I agree DIY is a wonderful thing, a great way to add dimension to the hobby. In practice the majority of the audio DIY people I have met (believe me, there have been many) achieve more in words than in practice. I judge it to be mostly counter-productive for the following reasons, and provide three examples to illustrate my points:
  • Most of the DIY products I have heard are deficient one way or another, sometimes seriously, rarely striking a fine balance. The more one focuses on boutique components, the more expensive components one employs, the more the likelihood of wayward results. The most important requirements for DIY, as in general, is not skills, but fine ears, good judgement and capability for self-criticism. Electronic and theoretical know-how is very important, but it is not the most important in this hobby that has a tinge of alchemy about it.

    Most of the DIY people spend too much time listening to components than music. Changing, running-in and comparing components is extremely time-consuming. Don't tell me that doesn't eat into your listening time. Listening to a few tracks over and over for comparison is not listening, not living - it is hell.
  • DIY tests the ego. Yes, we have all met many DIY people who claim they have made something that kicks butt, that beats the shit out of an established product, but have you ever met a DIY person who admits he is mostly failure? Judging from my experience, there should be a lot more of the latter than the former, but alas...The ironic thing is, if music comes first, DIY should not at all be an ego thing, and the least suitable person for DIY is one with a huge ego.
  • DIY can cost more. Almost all of the DIY fanatics have bad words to say about manufacturers. While it is true for the same money you can build something with much "higher grade" components, there is no guarantee that it will sound good, or even balanced. And there is little resale value. Expensive components add up quickly in cost. It is just as easy to end up with many machines, a huge number of components and no music than to arrive at nirvana.
  • Example - Marantz 7c (pic from Audio Classics) I think it is apt to cite just some examples to support my observations. The Marantz 7c must be the most popular choice for DIY preamplifier. Over the years I have listened to dozens of DIY efforts, some costing more than the real vintage thing or the re-issued version, and that is expensive! Many "improved" on the original circuit, often beefed up the power supply or even switched to tube rectification and regulation. In fact, for a year or two, when I fist came back to HK, I lived with a DIY version commissioned by me and built by my electronically savvy student using a cheap case, point-to-point wiring and good but inexpensive components. Sometimes I'd change a cap here and a wire there, though nothing excessive. Then I came across those much more "serious" efforts. To sum the whole thing up, my cheap one did not at all fare badly - at least it sounds balanced. Most of the over-built and over tweaked ones sound oddly disengaging, even incoherent. And certainly none came close to the original, which I happen to own! The original may not be the last word in every department (especially in dynamics) but it has a musicality that somehow eludes all of the imitations. Even the re-issue version made by VAC, which adheres much to the original (except understandably for parts) is much better than most of the DIY versions I have heard. In passing, I'd like to note that earlier ARC preamps that use 12AX7 have been said to be based on the Marantz 7c.
  • Example - Sun Audio 2A3/300B amplifier Back a decade ago, through my yahoo forum, I must have played a role in the popularization of Sun Audio kits, particularly in HK. I must say I have never met a Sun user who doesn't like his amp. But in the forum, where there are a lot of DIY people, including some well known figures, the very simple design did meet with various criticisms. Some of the people built kits by another kit maker (say kit B) and made every conceivable upgrades recommended by a respected electronic guru. A friend had a fully decked out kit B that used all manners of chokes and it went up against my Sun Audio. I personally feel, despite the simplicity, the Sun more than held its own. If not for my awkward position I'd call the Sun the outright winner. I wanted to support kit maker B and so did not really fully air my opinion. And what do I know about circuits to argue with the guru, who I also happen to like? As much as I respect electronic know-how, the experience taught me to keep an open ear, to say the least! My convictions were further strengthened when, over many years, I heard many decked out and not inexpensive DIY amps went up against the Sun amps. I am sorry to tell you all of them did not sound as musical. Now, I know fully well the Sun amps are not the ultimate in anything, and they are not cost-no-object designs to begin with, but they have continued to hold up amazingly well over the years. The designer had used his ears well and balanced things deftly to make simple yet engaging statements, thereby trumping much DIY grandiosity in the process. That is something called "art", which the majority of DIY people fail to understand.
  • Example - DIY loudspeakers At the risk of incurring much wrath, I have to say the most difficult thing to DIY is the loudspeaker, particularly conventional designs. As an example, II have met people who use the most expensive Dynaudio drivers and crossover components and put them into DIY cabinets to produce the most atrocious and unlistenable sounds I have heard. So, DIY multi-driver boxed speakers are a no no. Big horn assemblies fare better, as the midrange and treble drivers and horns don't really need housing and one only needs woofer enclosures (some even do without). Wideband drivers are also more likely to succeed, though it is by no means guaranteed. In the end, very few DIY loudspeakers (if any) are satisfactory in my experience
When to DIY?
All that said, let it not be misunderstood that I am all against DIY. Truth is, I admire many facets of DIY but also find much, too much, that is disturbing (same with manufacturers).In the end, cheap and Here are aspects of DIY that prove rewarding in my experience:

Build something that is not available I can never agree with people who build a "replica" of something that is available. Aside from Marantz 7c, few of the replicas I have heard (and they number in the hundreds) have personality. It can be based on the circuit of Matisse Atom, Jadis JP80 or whatever, but they all sound the same, sterile and devoid of character. Almost all miss the characters of the originals. Why target something to attempt to knock it down? Why does one have to prove he is better than the original designer? Build something new! It can be a brand new design. It can be a variation so that rare tubes like the WE275a, 205D, or 50, can be used. Come to think of it, time for me to do that for my WE275a tubes with one of my surplus Sun amps.

Make use of valuable but cheap old parts Forget about 12AX7, 6SN7 and 6DJ8 and use cheap and unrecognized tubes. Is that not the original intent of DIY, to make something cheap and cheerful? Why fight with the huge number of people who use these tubes? Why build another TDA1541 DAC? Why be so common if you have to DIY?

Judicious replacement of parts Since I have great respect for vintage equipment, my view on modification is guarded. I can never agree with modifying now expensive classics. They are expensive for a reason. Yes, replace what is necessary but no more. But there are a whole lot of inexpensive vintage equipment that would benefit from full restoration and modernization, to bring them back to life. Among modern equipment, DACs probably benefit from part replacement the most. I have heard a few DACs with upgraded OS-CONs and they do seem to work (I am more guarded when it comes to clocks). In general, the word here is "judicious", not "wholesale".