I have recently discovered that finding the perfect loudspeaker is an amazingly daunting task. I’ve explained in the first part of this saga what it was like finding a near-perfect pair of Quad ESL-57 speakers — what I consider the best sounding speakers ever.But, the speakers were only the first part of the equation. For the past few months I also have been trying to find the perfect combination of hi-fi gear (amplifier, pre-amplifier, tuner, CD and turntable) to go with the speakers. I think I’ve come pretty close.

During my quest, I’ve auditioned dozens of different components — especially amplifiers — and I zeroed in on some great sounding, affordable gear.

My 1962-era Quads still sound better than any other speaker I’ve ever heard. But, I’ve found that the speakers sound different with every amplifier I found.

I limited my search to components, which would not harm the speakers. You can literally blow a hole in Quads with amplifiers that are unstable or too powerful. Unfortunately, it’s way too easy to harm these speakers.To keep my own pair of Quads safe I’ve auditioned mostly low-wattage amplifiers both tube and transistor designs.

Quad made — and actually still makes — amplifiers that are perfect for the task of making music. I listened extensively to 70’s-vintage Quad 33 control and Quad 303 power amps.These were first-generation transistor models. Sound-wise they’ve held-up pretty well over the years. Actually, the 303 sounds very good — approaching the best of today's offerings. I like it much better than a pair of similar looking monophonic Quad 50E amps.On the other hand, the 33 preamp sounds somewhat dated. Surprisingly though, the 33 and 303, when paired with the matching Quad FM3 tuner, creates a system that is pleasant to look at and listen to.

Because of currently reasonable resale prices, used Quad 33s and 303s are perfect targets for upgrading.

Before transistors, Quad made some of the most terrific-sounding tube designs on the planet. Because the Quad II amplifier is still in great demand as used equipment, the current owners have decided to begin producing the amps again in China.

The new Quad II Classic is a 15-watt, monoblock design. That means you need one amp for each channel. Basically they are the same design as those made a generation ago — in the 1950’s. The new amps are fitted with a few modern-day parts to replace those that aren’t made anymore. The sound quality is smooth and clean.The new, matching Quad QC24-24 tube pre-amplifier I auditioned sounded pretty terrific in the system too.

I could probably install these new amplifiers — sit back and listen to the music — and be happy for the rest of my life. But, that would means I wouldn’t be inclined to try all the other gear out there. Quad II Classics retail for $2,700 for the pair.

I’ve tried other tube gear as well. Dynaco amplifiers, originally made in Philadelphia, are favorites of Quad speaker owners. I’ve spent lots of hours listening to my ancient Dynas including what some consider the best for the task — the Dyna Stereo-70 (35-watts per channel).I found that I actually preferred a smaller model — a Stereo-35 (17.5-watts per channel). It is considered, by many Quad aficionados, to be one of best sounding amplifiers you could use on ESL-57s.

I’ve been lucky enough to have two ST-35s to try — a classic one from the early 60’s and a brand new one — now being marketed as a kit by the people at DynaKitParts.com. Both old and new had the same tubes — a complete set of modern-day JJ-brand EL-84 and 12DW7 tubes.

Both old and new amps sound very similar and very good on the Quads. I think I’d give a slight preference to the newer version. It just sounded cleaner and better.
I highly recommend this amp-speaker combination. The new Dyna Stereo-35 kits sell for the reasonable price of $450-480. (Tubes and top cover are extra.)

I’ve also tried another well-liked amplifier based on tiny EL-84 tubes, the Music Reference RM-10. I was able to borrow an original Mark I edition from fellow Quad owner Robin Wyatt.This amplifier’s designer was able to squeeze 35-watts per channel out of the same tubes that produce 17.5-watts on the Dyna. Sound quality is top notch. Overall, I’d say there’s less “warmth” in the voices (compared to the new Dyna) but a much more warm bass register.

The Music Reference people are now marketing a new, $1,950 Mark II version. I haven’t heard it — but I’m told that it sounds even better.As for transistor amplifiers, I tried a number of low-powered, Class A designs. Class A means the amplifier’s transistors are always working at their peak. These amplifiers usually produce low amounts of power but an incredible amount of heat. People overlook the heat because Class A amps can sound great.

A classic, unmodified, first-generation Sugden A21 (10-watts or so per channel) integrated amp sounded good – but not quite up to today’s best. I didn’t get a chance to hear a modern-day A21 (yes, they’re still making these great amps.)On the other hand, I got to try a difficult-to-find Marantz PM-4 integrated amp which sounded really, really terrific. Integrated amp means it contains a pre-amplifier/control section as well as a power amplifier in one chassis.)

The PM-4 (15 Class A-watts per channel) is one of audio expert Ken Kessler’s favorites. The sound quality of this amp is amazing — especially on a set of Quads. If you can find one (good luck) grab it.I was also able to audition a Bedini 25/25. Popular in the early 1980’s, the Bedini is one terrific sounding amp. From the lowest lows to the highest highs (and everything in between, the Bedini has the ability to make the Quads sound like they’re playing somewhat louder than other amps. It’s an interesting phenomenon.

The Bedini also is the hottest-running transistor amplifier I’ve ever tried. Needless to say, this time of year the Bedini would not be my first choice to use all the time. (Unless I get a separate air conditioner unit just for the amp.)

I was also able to try the monster Accuphase A-30 amplifier. This is a mega-dollar, modern-day, 30 Class-A watts per channel powerhouse. When used with a matching C-2400 preamp as well as the superb T-1000 FM tuner the sound quality was some of the best I’ve ever heard anywhere.They should sound great. The C-2400, A-30 and T-1000 combination will set you back more than $21,000!

In the final installment, I’ll tell you what I’ve done to my transistor Quad amps. They now sound like they’re brand new. Actually, even better than new!

Hmm, interesting, someone whos actually an audiophile posting here. This was my main hobby for over 10 years, although my enthusiasm for it has dwindled with the knowledge of that the powers that be seek to destroy technology pertaining to home entertainment (they'd DRM loudspeakers if they could).

Anyways, a few comments from my own expertise on the subject: "You can literally blow a hole in Quads with amplifiers that are unstable or too powerful."

Not an accurate statement of the problem, and b) false. I'll rephrase: "You can literally blow a hole in ANY speaker with too LOW powered of an amp, or you can blow up an amplifier that is too unstable".

A few things, you want real sound quality? Ditch the damn pre-amp, period. I had a $2600.00 Conrad Johnson Premeire 14 tube preamp, and a custom made passive level control for $100.00 absolutely decimated the living shit out of the CJ in every way. The key is you MUST find a good volume control (Allen-Bradley Carbon based potentiometer, or Shallco stepped attenuator), and it needs to be the right impedance. The imp[dance of the pot will determine the output imedance of your passive box, it will be about 1/4 of the value of whatever your volume is set at at any given time.

This means that at full output, your output impedance would be 25,000 ohms, which is extremely high, and you would experience a loss of bass, and dynamic punch, as it would not be able to drive the power amplifier sufficiently. That being said, it is very helpful to try to get a power amplifier with a high input impedance, this will help your source drive the amplifier.

Forget solid state, forget class A/AB amps. With the exception of amps that utilize a circuit akin to the Tripath chip. Switching amplifiers, these mimic class A output, and are extremely efficient (not class "D" amps btw). I have a modifier Carver ZR-1600 amp. It has sound qualities of a McIntosh MC-60 monoblock with Telefunkens, with more dynamic explosiveness and neutrality. The MAC amps btw, are damn damn good, the one I just mentioned will blow away all the other amps that you mentioned, bar none, good luck finding a decent pair though, and be prepared to shell out cash that you could buy a used car for.

The issue in all honesty, in reality, is not about tuber or transistors, etc. It is about, what technology and circuit design does the LEAST to molest the music, as defined by your presumably sopmewhat trained ears. Forget measurements when it comes to amps, use your ears, don't listen to any hype, throw your stereophile subsciption in the fucking trash, use your ears.

PLayback: If your rich buy a VRS Revelation computer playback system, or try to make something like it yourself with a Lynx-L22 soundcard, quiet Seagate HDD's, Plextor Premium or 716A, extract your CD's to HDD and play thru that to your stereo (yeah you have to do lots of work getting a quiet PC etc lol--the soundcard btw is innately pretty much immune to PS and internal electrical noise from the PC).

Power filter: Im not gonna get into a big argument about these. All I will say is this, safety and peace of mind means as much to me as fidelity, my answer: ZeroSurge 20 AMP Series mode surge filter with spectrum WVR, get the TRUE 20 amp one with the 20 amp cord and a good 20 amp wall outlet. THis negates the fact that it uses an inductor as a filter and does NOT notcieably degrade dynamics, this is my opinion and these are my ears, but I believe it is a damn good choice, period.

Don't neglect cables but don't buy the hype, find someone who can custom make them for you for no more than $200.00 per interconnect (or less) that might sound insane, but I have personally seen how that much money can be justified, again, my opinion, do as you wish, just don't buy mainstream bullshit thats on the convers of magazines.

I could go on and on but I've covered enough for now.

Enjoy

"This means that at full output, your output impedance would be 25,000 ohms"

I forgot to mention this is with a 100K potentiometer, you MAY be able to use 50K, I dont know, but remember, your SOURCE must drive the passive level control, the impedance your DAC sees is what your pot is, the lower it is the harder it is for your source to drive it, and this can have its own problems. IMHO 90-100K is actually fine, and that with a 50K input impedance on my carver hasn't been THAT bad really, I get a fair amount of dynamics, but it would be much better if I had a 100K or 200K input impedance on my amp.

Just one other thing, the reason why listening to your music from an HDD (in a true lossless format) is superior to ANY cd player or transport, is because after proper extraction is done, when you play back from the HDD, you are completely eliminating ALL of the jitter that would have otherwise been introduced inevitably from a laser reading a CD in real time, that jitter is NON EXISTANT when done this way.

If you can, goto Las Vegas, NV to the next CES, and listen to the VRS Revelation if your in doubt, after you hear that, you will understand that all your life, you've never heard what music really sounds like, unless of course you are a musician or have attented purely acoustical musical performances. Nm the spelling errors, my keyboard needs to be replaced =)

ahhhh nice post
I will never forget my Tascam RSM270X Cassette Tape deck that had specs as good as a CD player. Sounded better then CD players with poor D/A converter...

"It is about, what technology and circuit design does the LEAST to molest the music" I agree somewhat but I molest the hell outta my EQ... In resent years Ive moved to playing music thur my stage PA, this is the way I like to color my sound. Not the highest fidelity, but yeah, 1200watts loud and clear!
"Power filter: Im not gonna get into a big argument about these. All I will say is this, safety and peace of mind means as much to me as fidelity" I agree! You will not belive the differance in grounding the chassis of ungrounded equipment untill ya do it. Why everything doesnt have a three prong plug I dont know. Keep yer PC, recording equipment, bass/guitar amps, and valued stereo equipment OFF the same curcuit breaker as yer 'fridge, washer, dryer or anything with a motor. My stuff has it's own outlet and own curcuit breaker not shared with anything else.

my keyboard btw is evil, I type in "you seem nice, wanna add me to yer list" and it sends out "nice font, wanna cyber?"