UMI 1:1 Sun Audio 300B VT25 ICL

Click pics to enlarge. Not exactly on this occasion but close enough. Station B in front. Center, Philips AK601 CDP and Melos 222 Preamp below Sun Audio VT25 and DIY 45 amps. Left, from top, Micromega Duo transport, Micromega Solo, Elekit 8230 2A3 amp, Philips cheapo CD-771, Micromega Duo Pro DAC, PS of Melos 222 and Bryston 4B. To the right, note the Ruark Crusader II in front of the B&W Matrix 801 Mk II. Note the "wall" on the right side was a partition using steel cabinets. In the back (actually near the entrance) is Station A. CDPs in use are the Revox 221 and Pioneer T-07A, second and third from top, below which is the MFA Magus B Preamp. Amp usually a Rotel 870BX.

Letter from Hong Kong (24-6): The Longest Days, Part III

Written in Shenzhen

Part I, our gathering on Jan 28th in Chaiwan

Part II, the next day, starting with the amazing den of Taimonsing. 

January 29, chez moi to finish

After being cooped up in the RCA Warehouse of Taimonsing, we had a late lunch. Then the 3 of us headed back to my old place in Pat Heung. Now you know why I fired up all my amps late the night before - in preparation for their visits! I planned out a program for them. Equipment was more or less as before (Station B described here; see Top Pic for Station A).

Program/Station A For a starter, I first fired up the B&W 801 Matrix Mk II. CDP was the Revox 221. Preamp MFA Magus B to the Rotel 870BX. I played mostly Until the End of the World. We didn't listen to this for very long as it's not the main program...

...then, after Program B finished, icefox the taskmaster asked for the Rotel amp to be replaced by Bryston 4B, which we did. Fortunately I was able to produce 2 XLR to RCA adaptors for use (no RCA inputs; there are actually a pair of professional TRX female sockets which I presume would take 1/4" phono plugs). With a lot more power than Rotel, the sound was drastically different, much fuller but less clean, the Rotel being faster in bass transients. But, as the 801 loves current, overall this was for sure an improvement. The Bryston had not been run for a long time, and it was probably a little murkier than when optimal, and there were occasional small popping noises...

...That was not all: see the UMI section below...

Program/Station B We spent the bulk of the time here. The Ruark Crusader II was used. CDP was the lowly Philips AK601 (CDM4/TDA1543). Preamp Melos 222. The program was to let them hear 2 Sun Audio amps, the 300B and VT-25, and an ICL/Softone 300B. Below you will find the reasons why I programmed it so.

Sun Audio 300B As mentioned before, this was built not on the 2A3/300B kit (2.5 and 3.5K taps) but on the Sun VT-25 kit, using the 5K ohm tap of the output trannies, so a "mismatched" amp of less than usual power (say between 4-5 watts). 6SN7's are a pair of old RCA's. As before, the 300B's and 274B are all 50's WE. The reasoning was to have them hear WE tubes. They have heard a lot, more than I (especially icefox) but not so often outside WE equipment or in humble SE amps. To my ears, this amp has the most WE qualities, including that elusive 撩撩吓 feeling. Many of the tracks on Until the End of the World have quite a bit of electronic ambient sound, swooshing and undulating. The effect is much enhanced in the amp. icefox incidentally might have found some of it a little "hea" (Cantonese for relaxed).

Sun Audio VT25  6SN7's are a pair of old suspended filament GE's. We heard first the white based WE VT25's with the WE 422A rectifier. The idea is also to hear WE tubes, albeit less famous ones (in particular, the 422A is much less regarded than the 274B). To my ears, sound was good (though some clipping is inevitable), but definitely less subtle and more yang than the 300B. And of course, sometimes the amp shows some clipping (1.x wpc)...We later changed to 274B and the sound improved markedly!

ICL/Softone 300B (here) I've always been an ICL/Softone fan. Very good designs for very sensible money, even now. The idea is to compare the WE equipped Sun Audio 300B amp with one using common tubes. The 6SJ7 (essentially a 6J7 without top cap) here is old stock glass GT with metal bass. 300B's a pair of old Shuguang's. Note that in its use of tubes this amp has a shade of the WE91A in it (though it is thoroughly modernized, with things like constant current source). Humble tubes. Sound is quite good, but modern, and certainly more powerful than the Sun.

UMI 1:1 Transformer (here and here) Surprise! I brought this one over from Shenzhen just for this occasion. The effect was unbelievable!

• Inserted between CDP and Preamp It immediately improved the performance - across the board. Wider soundstage and better dynamics. It helped to bring the Sun VT25 closer to the 300B, but what was truly amazing to me was that, when used on the ICL, it kind of brought the modern amp (with modern tubes) at least a little bit closer to the old Sun with WE tubes. The ICL amp suddenly became less a straight-shooter and a little more suave!

• In Station A Again, inserted between the Revox CDP and MFA Preamp, the sound took an unbelievable turn for the better. Pushed out envelope. Much cleaner and more dynamic! We played the Burmester CD2 (long oop; pirated on TB) and it was just fab! Taimonsing rated this one as the greatest improvement.

• I gave the UMI to Taimonsing to make the rounds among the circle as I want more opinions. I'm looking forward to the feedbacks! U shall read more in this blog in due time!

Comments

• WE 274B All agreed that this tube makes the most difference. In fact, although it's very expensive, the 274B in the VT25 amp gets my vote for the "best value" WE. Although the 274B is subtle, sinuous and tactile in its upper reaches it's amazingly powerful in the lower reaches. In fact, the way it fills out the lower end may be a character trait (I think Taimonsing will agree with me). If there is just one WE tube you should get, this is it.

• WE 300B Personally, I think the real WE 300B is just a phenomenal tube. For me, its sophistication is way over any modern replicas. But, as mentioned above, the 274B is even better entry into the magic of WE. It's the essential portal.

• SET? Now, you may not know that both my guests, Taimonsing and icefox, are not SET fans! In fact, at their dens, you shall not find any SET amps! All PP amps! Well, for the SET amps I demonstrated on this occasion, their comments are fascinating. "...don't sound like the usual SET amps we have heard..." I take that as a compliment! Yes, indeed, many SET amps are just way too lean and meager, but they are not for me.

• Sun Audio Tamura Another note here on Sun Audio and Tamura transformers. If you ask me, I don't think I can easily find SET amps better than Sun Audio at any price. They are just superb value for money, and its a pity that they are so low-keyed and invisible in the US market. Mind you, for this round, I also screened Elekit 2A3 and my DIY 45 Amp (WE412 driver, Tango trannies), but I did not offer them for tastings as I thought their sounds would not be exactly what my guests were looking for.

Pics of the Food the Night before

ICL/Softone Model 1 Bias Instructions 2A3 300B

Click pics to enlarge. Top, innards of ICL Model 1. Note the 2 trim pots to the right of the triode sockets (V103). Note to the pots' right are printed Plate Current (Max and Min). Note towards the Upper Right corner the test point TP1.

ICL/Softone Model 1 Bias Instructions

This post came about because my friend wosirsir, whose audio forays (Quads and then my Tannoy Canterbury and EAR 509) I have chronicled many times in this blog, sent me a wechat pic of ICL/Softone Model 1 that he's listening to (see pic below).

It must have been at least 20 years ago that I bought from Japan the Model 1 2A3 and rather liked it. I just loved the quirky look. Later, when a Model 1 300B became available on the second-hand market I also grabbed it. They are basically the same amps (maybe a few components have different values, likely the anode resistors, and slightly higher Plate Voltage for the 300B; of course bias current differs).

I had so many amps, like Sun Audio, that I spent very little time with my ICL's. But when I returned to Hong Kong in 2020, towards the end of my stay I decided to fire up my SET amps and Ruark Crusader III and was pleasantly surprised, even shocked, that they worked so well together. The ICLs just sailed with the Ruark‘s, very musical.

The Model 1's have long been discontinued and can only be had second-hand. Here's the problem. This is a FIXED BIAS amp, and when swapping tubes one must re-bias. This article is to show how to do it.

As I use old stock tubes I had to re-bias the amps. For my 2A3, I used RCA double plates. No, I have never tried NOS WE300B in my Model 1. I emailed ICL/Softone and they replied. So I was good. Some years later, my hard disc crashed and I wanted the info and wrote them many times with no answer. As a last resort, I asked on AudioAsylum and the good folks helped me out (Tre' had the same email reply that I had before, and he rescued me). Here it is again:

***The procedures of the adjusting current of Model1 amplifier******

There is a place of a high voltage in the amplifier.
Open the bottom panel.
You can see the two pots near by 2A3 Sockets on PCB.
Two pots are used for adjustment of the plate current of 2A3.
Pot is set for the plate current of 2A3 to 45mA.
The operation of 2A3 of us is as follows.
Voltage of plate 310V from 300V
Current of plate 45mA from 40mA
Load resistance 5K ohm

At first, set two pots to MIN position for setting the plate current
to minimam.

And,You can see TP1 terminal right side of PCB.
TP1 is an output of the high voltage stabilization power supply.
TP1 has the voltage from 310 to 315V.
The direct current resistance value of the output transformer of
Model1 is 120 ohms.
The current of the plate is obtained from the difference of the
voltage of TP1 between the plate of 2A3.
Pot is adjusted so that there is a difference of the voltage of the
TP1 between plate of 2A3 in 5.2V from 5.4V when the current of the
plate is adjusted to 45mA.

120ohms * 45mA = 5.4V

So as to wait for the stability of operation, you must watch the plate
current for 10 or more minutes.

Because it is a high voltage, the inside of the amplifier is
dangerous.
You mast pay attention and be carefully.

When the short-circuit even a little is occurred, the high-voltage
stabilization power supply is broken.
Please pay attention.

For Model1-300B amplifier.

Two pots are used for adjustment of the plate current of 300B.
Pot is set for the plate current of 300B to 55mA.
The operation of 300B of us is as follows.
Voltage of plate 335V from 325V
Current of plate 55mA from 50mA
Load resistance 5K ohm

Pot is adjusted so that there is a difference of the voltage of the
TP1 between plate of 300B in 6.2V from 6.6V when the current of the
plate is adjusted to 55mA.

120ohms * 55mA = 6.6V

So as to wait for the stability of operation, you must watch the plate
current for 10 or more minutes.

Application Notes: 1) You must have a load, so connect the upside down amp (make sure not to topple it, very easily done) to some loudspeaker; 2) Make sure the volume is ZERO; 3) Turn the Multimeter to DC Voltage; 4) Apply the Red Probe to TP1; 5) Apply the Black to Chassis; 6) Turn the Trim Pots so that they show the desired Voltage; 6) Keep in mind you can use the Formula to run the tubes even more conservatively, which I prefer. e.g, for the 300B amp, if running at 50 mA current, Voltage needs only be 6V.

This will not be the last of my articles on ICL. This article has a brief.summary.

Circa Dec 2020, HK. Front left, 2A3 - Note the Glass bottle 6SJ7, which is a MUST, way Superior to Metal Tube Stock. Front Right, 100V San Ei 6BM8 amp. Rear left, Studer A730, right 300B.

At Wosirsir

Tannoy Black Silver ICL Model 2 DAC Sun Audio VT-25

Click Pics to Enlarge: From Front to Back, 12" Tannoy Black's in DIY Cabinet; 12" Tannoy Silver's in HPD Cabinet; 15" Tannoy Gold's barely seen. 

Virtual Home Visit (3): Tannoy Rarities, Softone/ICL, Sun Audio and DIY Cabinets and Tube Amps

How Time Flies! Last time I reported on our Hong Kong Yumcha Friend K.C. was almost 10 years ago (here)! I have maintained a connection with them via our yumcha WhatsApp group, and it comes in handy during these tough times. You can look forward to many home visits down the pipeline.

Tannoy Black Silver Gold In that article I gave the details of his setups, particularly the extremely rare and expensive Tannoy Black drivers, so please read that for background as I am not going to repeat myself here.

Softone/ICL Model 2 DAC For Digital, K.C. has always used his trusty Philips CD-850 as transport. I sold him the Softone/ICL Model 2 DAC  (still sold here). IMHO it is excellent value for price. It employs a pair of 6DJ8 valves and can handle up to 24/96. Being a DIY'er, of course K.C. had modified it to his satisfaction (I'd change those Japanese brown caps). Should you like to read more on this small but interesting company, I have previously reported on Softone/ICL Models 1, 2, 3 here; I also reported on the Model 4 Phono here. You can call me a fan of this company.

Sun Audio VT-25 Amp Sun Audio is justly famous for their 2A3 amp, which my NYC friend Kevin also owns. It has two primaries, 2.5K and 3.5K and can be easily converted to 300B (I had both, but sold them before I left HK). But the VT-25 is a rarer bird. It uses a lower 8K for the VT-25 and also has a 5K winding, which can be easily converted to a 45 amp (I have done it for a friend). I had another one which I converted to 300B ("mismatched" impedance) and the result was excellent. This is rated at 1.2 wpc, and can drive the La Scala pretty well, but not so much Lowther or Tannoy Canterbury. I loaned it to K.C. before I left HK, and he said it surprisingly drives his Tannoy's very well. Note that the older Tannoy's are easier to drive than current ones.

DIY SE EL34 Amp

Below is a Chinese TV series which features on the sideline hi-end audio. This Lady

got to listen to a 40K RMB system and got the shivers. She borrowed the CD.

But in the next episode (plays automatically) she discovered it was not the same

on her computer,and she went shopping for a system.

Review: Verity Audio Rienzi meets Softone ICL

Click pic to enlarge.

Review: Verity Audio Rienzi III
1, 2, 3, Go! Softone ICL

OK, I admit it, part of the reason for the revisit was for the fantastic and wholesome breakfast: eggs, sausage, fresh carrots and cabbage, and home-made bread! Thanks and thanks again! How am I going to do without today! :-(

Before and during breakfast, we had round 1, which used the resident ASR Emitter I Exclusive. Since the sound was not much different from before, I shall not dwell on this part and refer you to my previous reports (here).

Mostly Softone ICL (official website)
This came about because our host Sang just acquired the ICL Model 3 CD player. Yes, contrary to what you read in the commercial press, many people still buy CD players! He wanted to play with my ICL Model 2 DAC and I wanted breakfast, so the visit was arranged. Since I have read that the Verity Audio Rienzi is friendly to flea-powered SET amps (based on a review in Ultra Audio), I decided to take along some extra stuff, and the challenger system was as follows:

Transport/CD Player: Softone Model 2
DAC: Softone Model 3
Preamp: Bryston 0.4B
Amp: Softone Model 1 (300B amp; discontinued; on the floor in the pic)
Speaker: Verity Audio Rienzi
Cable-Analogue: Canare (cheap 75 ohm) and Belden teflon silver-plated (looks like Cello String, but white)
Cable-Digital: Belden (yellow)
Cable-Speaker: Belden 9497
Cable-Power; generic

ONE OF THE MOST JOYFUL MOMENTS IN MY HIFI JOURNEY. Yes, in terms of fun and delight, not absolute performance. And vindication for Verity Audio also. Previously, I had not been too enamoured of Verity, indeed for all speakers of this kind, with one small speaker on top of a "subwoofer" module.

But, on this historic day, with the full system as described, the system cast a huge soundstage, with instruments reaching into the far corners (whereas the ASR only had the center, not even particularly full at that). Instruments gained presence and size, with beautiful and correct timber. Amazingly, the sound had excellent live presence. The voice of Buena Vista Social Club's Omara was smoky and the band swinging. In the duet of Ray Charles and Nora Jones, not only were the voices beautifully differentiated, they tightly inter-weaved to covey a feeling of duo partnership. Grappelli's violin was sinewy, and the system coveyed effortlessly the rhythmic finesse, as it also did with Take Five.

Even with the classical and bigger stuff, the system did well. Yang Tianwa's violin on this most delightful Naxos series was bewitching; with a good system, you should be feeling the bow's return as well as the finger's action, and I did. The orchestra accompaniment had good weight. Musica Antiqua Koln was swinging in this wonderful account of the Brandenburg's. Even more impressively, the second movement of Shostakovich's Fifth Symphony showcased the gutsy playing of the lower strings and very good dynamics. The only track that exposed the limited power on hand was a closely miked piano track.

Now a few words on particular components in the system. I shall not be exhaustive as I am sure I will write a Softone/ICL overview one day:

Softone Model 3 This is a wonderful CD player as well as a transport. Using the same Philips CDM Pro2 laser mechanism, I wonder why people buy over-priced transports like Orpheus and Weiss. As a CD player, the sound is refined and very clean.

Softone Model 2 This is a best-buy DAC that handles up to 24/96. Being tube buffered, the sound is warmer and weightier than the Model 3, and hence likely more suited to the high resolution Rienzi.

Bryston 0.4B This is a surprisingly musical preamp of older (and better imho) vintage. It has absolutely nothing "transistory" about it. To this dedicated tube preamp user, this is the highest praise.

Softone/ICL Model 1 This is a surprisingly sophisticated design (as most ICL products) 300B amp (there is also a 2A3 version) of fixed bias design, with 330V at the plate and the 300B run at 65 mA. Surprisingly, using only small output transformers, it can be driven very hard and outperforms many a costlier SET amp. Since I had not used it in a long time, I randomly took a pair of Chinese 300B and tested it in the morning. I measured it to make sure it was not over-biased. Boy, it was only running at 33 mA, lower than you'd run a 2A3. You know what? I did not re-bias since it sounded just fine with my Tannoy. So, this amp now is running at much less than full power; I'd estimate only outputting 3 watts or so.

Verity Audio Rienzi This experience completely changed my view of VA. Previously I had heard several pairs at shows and in homes. At best I'd say they were hifi-ish, not particularly attractive (I'd say the same about the over-rated Wilson Watt/Puppy). I had even heard a higher model driven by a full Monty DIY EL34 amp and the sound was sleep-inducing. So imagine my surprise this time. The Rienzi is lightning fast and superbly transparent. It may be a trifle too bright for my taste but I think that can be easily rectified. More importantly, unlike most Wilson Watt/Puppy, the two boxes appear to be coherently integrated (although not so when the ASR was used). Most surprisingly, it has excellent rhythm and pace as well as a live presence, very rare qualities in loudspeakers.

The Rienzi is obviously a tube and SET friendly loudspeaker. Given the already mightily impressive performance with the lowly Softone/ICl amp, I would say it is a marriage made in heaven. My great happiness is not only for the host, but also because I am happy there is another good loudspeaker for SET amp users. There is no way I personally would use this speaker with anything else but tubes, and preferably SET amp at that.

Of course, the Rienzi is still not a large, nor fullrange, speaker, but given its modest footprint it is a worthwhile effort.

Epiphany!

Review: Leben RS28CX and RS-100 Preamplifiers

pic from Audio Asylum: RS-100 on top of RS-28CX

Review: Leben RS-28CX and RS-100 Preamplifiers
Vinyl Talk: Leben vs AN Kit vs Softone/ICL

As you know, because of my preference for SET, I have always been interested in boutique Japanese tube manufacturers. Even after the pinnacle of Kondo, now my reference, my interest in other manufacturers remain.

I have to admit that my interest in Leben previously had not been particularly great. Contrary to others, I am not exactly a fan of its golden looks. Leben makes only push-pull amps and I am not interested in those. Hence, the only area left for me to explore are their preamplifiers. As a vinyl man, the one I was interested have always been the RS-28CX, but my journey started with a borrowed sample of the line preamp RS-100, a product that evolved from the RS-28CX. I was grateful for that opportunity, which allowed me to gain the all-important initial insight. Ancillary equipment used in evaluation:

Digital: Audio Research CD2 as transport/Genesis Digital Lens/Musical Fidelity M1 DAC
Analogue 1: Kuzma Stabi S/Stogi S + Midas Denon DL-103
SUT: Denon AU-1000.
Phonoamps: Audio Note Kit MM Phonostage (older version); Softone/ICL Model 4
Connection to preamp: I used my best cable, the incomparable Kondo KSL-LPz.
Preamp: Leben RS-100 line preamp (info) on loan to me
Amp: Elekit 8230 amp (2 wpc 2A3 amp)
Loudspeakers: Tannoy Canterbury.

RS-100 Line Preamplifier (Official literature)
Like its bigger brother RS-28CX, from which it is derived, the RS-100 uses 2x 6CG7 in SRPP mode for amplification, but its tube rectification is by 6X5 in lieu of 5Y3. There is also a "U" version that employs 12AU7 instead of 6CG7. You can find out all the details from Jeff Day's review in Positive Feedback. It is a handsome unit and I prefer its size and hammertone finish of the top plate to that in its brethren.

The loan period coincided with my evaluation of the Audio Note MM Phonostage Kit, and you can read about that in my previous article. Here I'd add some brief descriptions. The sound of the Leben is utterly lucid in the entire frequency spectrum. Noise level is extremely low. The sound is neutral, without much tube coloration, which is how I like it. Dynamics have an unforced quality, with full, clear bass, good rhythm and pace and microdynamics. In my 200 ft LR and with my flea powered 2A3 amp I need to turn the volume knob to 11-12 o'clock to get the volume I need. This is in marked contrast with my other preamps from Japanese SET manufacturers; with the Kondo and Wavac line preamps, the volume is plenty loud already at 9 o'clock. Considering the SET amps all have very high input sensitivity, this is understandable as Leben does not make SET amps, rather higher-powered PP amps.

Since this is purely a line stage, there is a direct in feature, which was what I used. There is a set of variable output (with a knob at the back) but as you'd expect it did not sound quite as good as the fixed output. Unusually, there is also a Stereo/Reverse knob!

I did do a brief comparison with Kondo. No, there was no miracle. The Kondo just had more air and that je ne sais quoi quality, and was even more dynamic. But, keep it in perspective, the RS-100 remains a wonderful piece.

RS-28CX Full-function Preamplifier (official literature)
This flagship preamplifer has been in existence for much longer. For details, read the same Jeff day's review in 6moons.

By chance a second-hand unit became available here and I purchased it. You might remember that I have reported a little on this preamp's phonostage performance in my recent article on LFD (here).

Where the RS-28CX really diifer from the RS-100: Not surprisingly, while the sonic signature is close to the RS-100 (that is not much signature), there are important differences not explored Jeff Day's reviews. The integral part of the difference is due to the difference in gain structure of the line stage: the RS-100 has 23 db of gain, with maximum output at 53V; the RS-28CX line has only a little more gain at 25.2 db but the maximum output is much increased at 80V.

So while the line sections of the two superficially seem similar, they behave quite differently. With the same equipment, I need only to turn the RS-28CX's volume pot to about 9 o'clock to get the volume I want, bringing the preamp in line with my Kondo and Wavac. The reason for this is undoubtedly due to the presence of the phono section (keep in mind Kondo and Wavac all have separate phonostages).

This major difference in gain structure also makes the sound different from the RS-100. The higher gain undoubtedly is more suitable for my SET amps: the sound is more dynamic, more nuanced at low volume, more vital. Not a huge difference, but instantly audible. It is still not quite Kondo, but the difference narrows a little.

I think if you are a SET amp user, or your amp is low-powered, or have inefficient loudspeakers, even if you do not play vinyl, the RS28CX will likely be a better choice than RS-100. But for Leben amplifiers the RS-100 may be as suitable for digital-only users. Given Leben's integrated amplifiers are basically amps with passive volume, I'd also advise adding a Leben preamp and use the integrated as an amp (volume at maximum) if you want to upgrade the sound.

The phonostage: On Leben's website and in the reviews, there is a lot of hooplah on the superiority of the NFB-less CR type phonostage. IMHO this is over-hyped. CR types are actually not uncommon in modern tube phonostages; my Softone/ICL Model 4 is just such a device.

I had a hard time removing the tube shields of the 2x 12AT7 in my unit. Someone had applied some gluey substance to the tubes and after drying the shields were hard to remove. I had to chip away carefully. I wonder whether this was done at the factory or by a previous owner. I replaced the stock green-latter GE tubes with much older GE black-plate 6201's to great effect.

The gain of the phonostage is spec'ed at a VERY low 20.2 db. Together with the 21 db gain of Denon AU-1000 SUT, the gain of the phono section is only 41.2 db. But let numbers fool you, the truly amazing thing about it is that it sounds like twice that! With either my 0.3 Denon DL-103 or 0.47 Ortofon Kontrapunkt C, I only need to advance the volume knob to barely past 9 o'clock, about the same as using digital sources (here thanks to the high gain line section). It is also superbly quiet. Wonderful!

Which leads me to ruminate yet again. I have seen so many vinyl people calculating gain based on manufacturers' data and debate theoretically on whether a certain phonoamp is suitable, but let me tell you many of the (mostly transistor) devices just sound like less. Or shall we say there are quite a bit of inflated figures out there. Theory and data is one thing; listening is another.

Comparison with AN Kit MM Phonostage and Softone/ICL Model 4: Not to mince words, used with the Denon AU-1000 SUT, the sound of the Leben RS-28CX phonostage is decidedly superior to either high-value phonoamps. In almost all parameters, so no more elaboration.

Previous owner's setup
RS-28CX is seen here with re-issue McIntosh 275, driving Tannoy Stirling. Sound was not bad!