Premier 5s Inbound!

[AnotherJohnson]

The time of return is long long past.
But if the P5s can’t beat the Futterman OTLs, the P5s are definitely not up to snuff. Retubing is an expensive path, but may be the required fix.

Tubes may have low hours, but long age, and they can lose vacuum over time. This is one of the many problems that surface with putting very old amps back into service.

[AnotherJohnson]

I just noticed the Atma-Sphere connection to the advice.

It reinforces my time saving suggestion above.

And regarding the transformer taps, it came with G-4-8-16. Not posts though. Maybe he added the posts.

[SolderSlinger]

Consider Shuguang EL34M tubes. I've seen them around $17.00 ea. The M version is a real Pentode unlike some of the latest Russian reissues.

I've used Shuguang 6550 tubes in the past. I was very impressed with the tight matching and bias stability. Good sounding tube too. I haven't heard the EL34M so I can't provide an opinion.

[Boxcar]

Thank you for all your responses! Much great info to sift through!

For reference, my current system:

Digital: dCS Network Bridge into a Mytek LIberty II DAC
Analog: Marantz TT15-S1 Turntable with upgraded microline stylus on the Clearaudio Virtuoso Wood Cartridge
Preamp: Conrad Johnson PV5 upgraded with Jantzen Superior Caps in place of the blue EPCOS ones that were stock as well as upgraded foil caps in the power supply in place of the electrolytics. Preamp sounds much more open and detailed than stock while still having the CJ magic.
Power Amp: NYAL Moscode 600 Maxi w/ upgrades, PS Audio 200CX, Conrad Johnson Premier 5s with Teflon Caps and Thalmann upgrades.
Speakers: Martin Logan Ascent with upgraded crossovers (Jantzen caps in place of Solens) and new electrostatic panels in 2021.
Cabling: Mixture of Cardas Golden Cross and Cardas Quadlink for analog. Final Touch Audio AES/EBU for digital. Audioquest Vodka Ethernet.

First off, a response on "Do I know what I want?". I want my system to sound like the front row of a small jazz club. I'm heavily into jazz and play jazz on my system about 90% of the time. I also listen to solo acoustic piano most days when working from home, so a system that accurately presents the sound and presentation of a Bosendorfer is desirable. I want a system that sounds acceptable with "less than" recordings because many vintage jazz recordings aren't recorded all that great. I'm not into overly hifi sounding systems. Even sitting in the front row of a jazz club I struggle to hear all the nuances of a drumstick hitting a cymbal, so an overly detailed presentation doesn't sound realistic to me. I also want a system that has adequate pace, rhythm and timing to play some funk, rock and roll, or Metallica on occasion without sounding strained or lifeless. I've been a musician for 40 years and have attended myriads of live performances, so I have a pretty good idea of what live music sounds like.

For Admin: Yes, i've heard of people using autoformers with Maggie's, too, for essentially the same reasons as people use them with electrostats. Maggies are planar magnetic speakers, so they are slightly different, but my understanding is that they have similar issues with being driven to electrostats.

Thanks for the tube recommendation, SolderSlinger! I'll definitely check out the Shuguang EL34Ms, especially if they can still be had for $17 ea!

AJ - A note regarding the Premier 5 connections - Bill Thalmann modified my Premier 5s to have all Cardas input and output connections, so Cardas RCA input jacks and Cardas binding posts in place of the original screws. The binding posts are set up for Gnd, 4, 8 and 16 ohms. I have been using the 4 ohm taps with my Martin Logans.

Also, I do not have a Futterman OTL amplifier. The amplifier I have is a NYAL Moscode 600 that has been fairly heavily modified from what I can tell. It doesn't sound slow and veiled like the stock Moscode 600 does. The original Moscode 600 took the initial gain stage from a Futterman OTL (with the tube voltage regulation) and married it to the output stage of what is essentially a Hafler DH500 power amp. The concept was driven by Harvey Rosenberg as a way to get OTL sound that could drive electrostatic speakers because OTLs struggled severely with electrostatic speakers due to impedance issues. Per my understanding, OTLs are notoriously finicky when it comes to speakers and most modern speakers will not work well with an OTL, hence the concept of the Moscode amplifiers as a way to address these issues.

The autoformer question always seems to create some intense opinions and discussion. This link on Audiogon is a great example -> https://forum.audiogon.com/discussions/ ... c-speakers. Ralph Karsten (the president of Atma-Sphere who recommended the autoformers to me) contributed to this link and was roasted for his opinions, even though he made a good case (in my opinion) of how autoformers could be beneficial. He also explained that Martin Logan made a conscious decision to lower the impedance on their speakers below what was typical of the previous Quads / Sound Labs / Acoustats. I thought that was interesting. The reason I bought the Premier 5s in the first place was because another audio buddy of mine was running Acoustats and had bought some VTL 225 monoblocks to drive them and really liked how they sounded.

Right now, I'm leaning toward a retube and possibly having the amps serviced, after which I may try the autoformers or potentially different speakers. I'm curious if my Quintessance friends would let me bring the Premier 5s in on some weekday afternoon to try them on some of the speakers they have there once I retube them? Would certainly be a fun experiment!

Thanks!

Boxcar

[AnotherJohnson]

Yes, I remember your modifications from last year.
To me Julius will always be at the root.

Duplicating a small club setting is one of the easiest things to do. It really is simple. In all of my systems since the mid ‘80s, the small jazz ensemble has been the first thing to snap into place. I think you’re making this too hard.

As for Atma-Sphere and the Autoformers … it all comes down to your ears, your system. The whole purpose is to present the music in a way that pleases you. Nothing more.

Some guys really do want to have something that is unique. There’s nothing wrong with that. It’s part of the hobby.

[Big Dog RJ]

Ok BC that's great to know that you know what you're looking for in a playback system. Like I said, it's not an easy task to put together any highend system, it takes years!

Now the good thing is that you love jazz! So do I!
It also seems that you like to listen to the other stuff once in awhile as well, just to experience good music, that's great.

I will say this though, in order to recreate a small jazz club in your living room / listening space, you really don't need 200w tube monoblocks. That can very easily be achieved with just 30 - 40w the most. Therefore, I'm not sure if the Prem5's were the right choice. In this case, if it's a small type ensemble you're after ... or the occasional rock & pop stuff, either the MV60, Classic 60 or even the CAV45 would have been far better than vintage Prem5's.

Although HomerDk had the amps in good working condition before shipping across, there's something a-miss according to your findings. It lacks energy, no sparkle, not much definition and lacks PRaT, which is very important to you!
Even though this may seem to be an Output tube scenario, I would do a full tube replacement (including all signal tubes). After doing this full tube replacement and if the amps still sound dull and lifeless then there are other areas that need further attention. Could be power supplies, caps, resistors, voltage rails weak, current reserves wearing etc., basically vintage syndrome settling in.

This would involve a complete overhaul, which can be done but will cost you a pretty penny. Probably more than what the Prem5's are worth. However, this is the thing; after purchasing these beasts, you can't "un-ring" the bell... it's too late for that. So this is where "I" would do whatever it takes to bring these beauties back to full spec, which is a complete overhaul and will cost a fair bit, there's no denying that.

The thing is, if I had bought such vintage gear, after having spent a certain amount, I would except some issues along the way, simply because they're vintage. Then I would rather keep them for as long as possible and bring them up to full spec with some nice parts and upgrades. In this case, your Prem5's have already been upgraded to Teflons and some other tweaks... So why are they sounding dull is the question.

A similar scenario with one of the very vintage Manley Labs REF350's I had few decades ago. One monoblock blew an Output tranny because I biased the KT90's the wrong way. The other monoblock blew a small flat-pack tranny due to few resistors failing after a tedious bias procedure, which took me nearly an hour and wasn't working properly until the little tranny blew. Then I had issues on both amps with a very rare type of Driver tube. So I made a list of things that needed attention and sent to to Eve Anne. She replied the following day and within two weeks all the necessary parts and gadgets were shipped directly to me, including spare fuses and a spare pair of brand new KT90's just in case I needed backups. Now that's service!
All these things and work on the amps cost me nearly more than what the REF350's were actually worth. However, once all done and the final monoblocks were in place, boy did they sound bloody marvellous! They drove my mighty Infinity IRS 1B's and the Epsilon to glorious levels AND so did the Prem5's! So I know these amps quite well, and they have Stiff Power supplies, so there are absolutely NO problems in driving stats or any difficult loads.

Those Prem5's can really drive and control speakers, they just require some attention and hopefully it's not a complete overhaul, rather just a tube replacement set.
If they're worth to you keeping then I would seriously recommend a full tube replacement.

If they're not worth spending on or keeping, then SS would be a much more cost effective solution or any of CJ's Classic 60 series will do just fine.

Cheers BC, hope you get there at the end.
RJ

[Boxcar]

Good day CJO friends!

As always, thanks for your responses. All very helpful!

That's a great story about the Manley REF350s, RJ! Whatever happened to them after you got them working again?

So, after a ton of research, I've theoretically determined it's the ML Ascent speakers. While I've been unable to find an actual review with measurements for the Ascent, there are several reviews for other big ML hybrids from the same era (Prodigy, SL3, Montis, etc) and all clearly state they are extremely difficult to drive with some reviews stating that an amplifier needs to be 2 ohms stable to drive them successfully. A Stereophile review of the Sequel IIs had them being shipped between 4 different reviewers trying to find someone who had an amp that could drive them.

An example (also from Stereophile):

The Martin-Logan's (SL3) B-weighted sensitivity weighed in at an estimated 85dB/2.83V/m. This is somewhat lower than the specification, but in a room the line-source behavior of the panel will mean that the SL3 will sound louder than a similarly specified point-source speaker. Its impedance (fig.1), taken with the woofer switch set to "Flat," reveals it to be a hard load for the partnering amplifier, which might partially explain why WP found it very revealing of amplifier quality. Though the impedance drops to 1.5 ohms at 20kHz, there isn't much musical energy present up there, meaning that the amplifier will not be taxed too much. In addition, as is typical, the lowest impedance magnitude coincides with a phase angle of 0 degrees.

Fig.1 Martin-Logan SL3, electrical impedance (solid) and phase (dashed) with woofer switch in "Flat" position (2 ohms/vertical div.).



Figure 1 shows some wildly varying impedance and phase angle shifts on the SL3. Based on my research, it seems that the big MLs hybrids from this era would only really work with a handful of amplifiers, and they pretty much only worked with large brute force SS amps like Krell, Levinson, Threshold, etc. I'm surmising that this was one of the reasons ML went to a powered woofer (along with improved integration) as it doesn't present as difficult a load or the load can be tuned more though the crossover to accommodate the electrostatic panel.

Almost every reviewer I came across had to find an amp that produced well over 100wpc in order to get the early 00's big Hybrid MLs to behave. I'm guessing this is a function of the crossover needed for an electrostatic / dynamic hybrid speaker and the impedance phase angles associated with driving an electrostatic panel (capacitive load) and a woofer (resistive/inductive load) at the same time. It seems CLS's don't suffer as badly from this issue, and I've had personal experience with the Aerius that shows it doesn't suffer from this issue. I was powering the Aerius with a Quicksilver GLA (40 wpc tube amp) in the early 00's and it worked wonderfully! The Aerius is a much easier load. This aligns with what RJ and AJ were saying in that only 40-60 wpc is needed to portray a jazz club with the right speaker / amp.

I also found this on capacitive loads from an Agon post:

Severely capacitive phase angles (edit: electrostatic panels often have these), especially if they occur at frequencies for which the impedance magnitude (the number of ohms) is low, are particularly demanding on the amplifier. In part because reactive phase angles lower efficiency, as was mentioned. And also because the current drawn by a capacitor increases in proportion to the rate of change of applied voltage, which results in larger demands for current when fast transients occur than would otherwise be the case. The current drawn by an inductor, on the other hand, varies in proportion to the "integral" of applied voltage, which is not as challenging to the amplifier.

RJ, I totally hear you on unringing the bell and that I've jumped off the ship and now just need to swim because the ship isn't coming back. I'd LOVE to get the Premier 5s working, such that I may be willing to switch speakers (my lovely lady would not approve as she loves the MLs, so there's that lol). I love the sound of EL34s and big CJ EL34 amps are what dreams are made of for me.

I also did some research on the Martin Logan owner's forum regarding autoformer use, particularly with tube amps. It seems some people thought they were a godsend while others thought they didn't really help at all. One person thought they were initially a godsend, took them out after a few years and drove on, then put them back in a few years later and "found what he was missing". How we hear is such a strange thing!

So here's what I did after all that:

I ordered a set of the Zero Autoformers. They come with a 60 day money back guarantee, so if they don't work out or don't help that much, I can return them and be out about $25 for shipping. Not bad to try something for 60 days!

I also ordered a complete set of EL34s for the Premier 5s. I ordered the EL34C PS Vane tubes from Viva that go for about $220 an octet. I had replaced the smaller signal tubes in the Premier 5s with tubes from my stash earlier when I was first having issues with the amplifiers and didn't really notice any difference, but I wasn't willing to take the plunge and drop $800 on 16 EL34s at that time (what they were going for).

The plan is to get the Premier 5s out of storage and hook them up and see if I hear the same things as before. Then I plan to try the autoformers and see if I hear any difference. Depending on what I hear, I will install and bias up the new EL34s. I'm hopeful that every step will result in a marked improvement in sound.

I'm anticipating having everything before the weekend. Excited to try it all out!

Boxcar

[admin]

I'm definitely interested in hearing what you think when you have this all setup.

I'm still questioning the autotransfomer benefit but let us know your thoughts.

As for driving the ML and amp selection. I think they are "hard to drive speakers" in the bigger scheme of things. But it's gotten a lot better. You mention that the SL3 is rated at 85 db. Their newer lines are in the +90 db range. I was listening to a 13A driven by some modest amp (don't recall which one specifically but it was under 100 watts) and it sounded darn good. Granted they were playing mostly classical, but there was some rock in there as well and I never got the sense that the sound was strained or any clipping. I wouldn't put one on a 30 watt amp, but if you plan to play it at modest volumes I think you can get away with many more options today than back just a decade or two ago. The crossovers have also significantly improved in their line. They have an engineer over there (last name is Vojtko) and he has been with the company a long time and is the guy behind their new tech and improvements. The crossovers in these speakers is where a lot of the magic happens. It's very difficult to meld the ESL panel sound with a conventional woofer. Nobody has done this better (IMHO) than ML. A lot of people try to put a sub next to their planars. None have sounded as uniform to me as what ML does in their single package.

[Big Dog RJ]

G'day BC mate, trust all is ok at your end of the woods...

Yes, certainly sounds like you'd prefer the overall tonality of the EL34's config. Keeping that in mind, a large bank of EL34's, such as the Prem5's shouldn't have any issues driving difficult loads, plus with a stiff power supply, should be a breeze.

However, as you mentioned about the ML Ascents, these are quite big and perhaps more difficult to drive than the newer ML hybrids. The Ascents look very similar to the Prodigy's. The last time I heard a Prodigy stat driven optimally well were with huge VTL's, somewhere around 700w of tube muscle. So comparing those with the Prem5's, there will be vast differences in headroom and current reserves.

Of course once I had the Prem5's upto spec, I sold them off to another customer who was also using Apogee's but refurbed, so not as difficult. These were the much smaller Duetta's and the Prem5's were a perfect match at the time.
Later on, when we took delivery of the mighty Apogee Diva's, we used them primarily with CJ's Prem8A's, so that high power of 300w of tube finesse posed no issues at all.

I'm not sure if the Ascents have powered subs...? Looks like they're not I'm thinking, then in which case the Prem5's may be taxed to drive these hybrid stats full range. Is there any way of using the Prem5's on the mids & highs section and perhaps a SS amp on the bass section?
I know this is not ideal but at least the Prem5's won't be under stress than compared to driving these hybrids full tilt.
Do you have to use a crossover or can you utilise the internal crossover in the Ascents?

Re. To my Manley Labs REF350's, once I got them upto full spec and working order, I sold them to a band member who owned a night club in Colombo town. He would fire up those huge Manley monoblocks and blast out tunes from 7pm to 4am driving his professional JBL's that were suspended from the ceiling. The sound was fabulous! Powerful and clean, no distortion just pure thump and the JBL's really took a different dimension after installing those Manley amps. He was thrilled! Still has my amps but no night club. Last I heard from him is that he was using my old Infinity Epsilon speakers, which I sold years ago... so looks like he's keeping that particular combination, which reminds him of those night club days. According to him he says that it sounds very lifelike and no other system can do. Arnie Nudell was capable of doing exactly that!

Cheers BC, let us know how it goes.
RJ

[Boxcar]

Good day, CJO brethren!

My apologies for being slow to update on my progress. It's been quite a journey, and I still don't think I'm done.

That's wild on the REF350s, RJ! Had to be quite the night club setting! I bet it did sound awesome. Entirely different experience driving pro speakers with a true audiophile amp, I'm sure! There's a bar in Milwaukee that I used to frequent when I lived up there that had all vintage McIntosh gear next to a 200 gallon fish tank behind the bar. The place was super dark so all you could really see was the lighted fish tank and the glowing green McIntosh lights. Very cool place.

The Ascents do not have powered woofers. From what I can tell, the earlier fully passive ML hybrids like the Ascents are the most difficult to drive. The CLS's are easier as are the modern hybrids with the powered woofers. As I mentioned earlier, the difficulty driving the passive hybrids seems to be due to the greatly varying impedance characteristics of the stat panel and the woofer as well as the crossover implementation. It is possible to biamp the Ascents with a solid-state amplifier on the bottom. I haven't tried it yet, but I do have a couple of amplifier candidates I could try.

On to the autoformers!

I've been running them about 3 weeks now with the amps being on nearly 24/7 to break in the autoformers. I still have the original tubes in the amplifiers although I do have a full set of EL34s ready to roll in once I feel things are dialed in. My thought is "Why waste hundreds of hours of burn in on new tubes?". I'm currently using some inexpensive Amazon speaker jumpers made with Canare cable to jumper between the stat panel binding posts and the woofer binding posts on the speakers with the autoformer connected directly to the stat panel. I am not using any sort of speaker cable. The signal goes directly from the Premier 5 output terminal to the autoformer to the speaker. I haven't tried other settings where I split the difference with the autoformer hooked up to the one pole of the woofer and the opposite pole of the stat panel and then jumpering the opposite poles. Perhaps something for the future.

The autoformers have the ability to multiply the speaker impedance 2:1, 3:1 or 4:1. There are also some other fractional combinations that could be used but I haven't tried those.

My first experiment was running the 2:1 autoformer winding and hooking the Ascents to the 8 ohm tap on the Premier 5s. This would act as though the Ascents were a 4 ohm speaker, but uses the 8 ohm winding on the output transformer of the Premier 5. I immediately noticed an improvement in bass response, and it wasn't subtle. There was also some improvement in the imaging, and it sounded less smeared.

My next experiment was using the 4:1 autoformer winding and connecting it to the 16 ohm tap on the Premier 5s. This would also act as though the Ascents were a 4 ohm speaker. With this setting the sound became overly tubey and a bit slow. The bass was also more mushy. It sounded as though it was over damped.

My next experiment was using the 3:1 autoformer winding and connecting it to the 8 ohm tap on the Premier 5s. This would act as though the Ascents were a 2.7 ohm speaker. With this setup the bass improvements came back from the original experiment (2:1, 8 ohm tap) and the midrange greatly improved. Voices became very lifelike, and the soundstage no longer sounded smeared.

My final experiment was using the 4:1 autoformer winding and connecting it to the 8 ohm tap on the Premier 5s. This would act as though the Ascents were a 2 ohm speaker. With this setting the sound was strained so I went back to the 3:1 winding on the 8 ohm tap. I've left it with the 3:1 autoformer winding on the 8 ohm Premier 5 tap since.

During the last 3 weeks, the sound has continued to change for the better. I'm not sure exactly what might be causing the changes. It could be the autoformers breaking in, perhaps the Premier 5s further breaking in after sitting for so long, or I'm thinking it may be possible that the teflon caps that were installed by Bill Thalmann were never fully broken in. One area that has greatly improved is the high end. Things like triangles and bells and even the upper range of a piano have a clarity and crispness that I've never heard from my system before and I've only really heard in systems that are an order of magnitude more expensive. Vocals, especially female, are magical and it sounds like the artist is literally 6 feet in front of you. My lovely lady and I saw Melody Gardot live a few nights ago in Chicago and she turned to me during the show and said "It sounds exactly like it does on your system." She was right, the vocal sound was amazingly close. The Premier 5s don't have the depth of soundstage that the Moscode has, but I think this is a good thing as they sound more intimate. Also the Premier 5s don't have as much air around the instruments as the Moscode, but this is an area that has been improving during the break in process.

I'm curious if things will continue to improve and when I should roll in the new EL34 tube set I have for them.

Now if I could just figure out a way to make the autoformers physically disappear so they would have a better WAF that would be swell

At this point I'm quite pleased with the progress. Every review I've read on the Premier 5s says they sound wonderful on vocals and have a magical high end, but I just wasn't hearing that before the autoformers. Open to ideas on when I should roll in the new tubes! I'm also considering rolling through all my earlier autoformer experiments again since I've heard changes in the sound since I originally performed those experiments.

More to follow....

Boxcar

[admin]

The older hybrid ML models without internal amplifiers were significantly harder to drive than more modern offerings. Perhaps that made autotransformers more applicable to that design? Certainly an interesting thing to play around with to see what the maximum performance you can get out of the speakers. These autotransformers are not inexpensive and there is a careful line when the autotransformer costs more than the speaker on the used market, are the funds better suited to augment the sound of older speaker vs the price of getting something newer/higher up the line.

It also begs the question of whether some amps respond better to autotransformers?