Premier 5s Inbound!

[admin]

It's upto to you, and only you can determine whether it's worth the cost. All the best,
RJ

RJ is probably right. There is a good chance that new tubes are going to give the results boxcar is looking for. But as my comment says above, it is literally the worst time in history to buy new tubes. And the Premier 5 has a lot of tubes. If money is no object, then tubes are probably going to be the way to go but it would not be unreasonable to try everything else before biting the bullet on a large purchase like re-tubing.

[Boxcar]

Hey Gents!

Thanks for all your great feedback! I agree, at the moment, I think it makes more sense to try some tweaks than it does to head straight to biamping, although biamping wouldn't be too difficult for me to set up and I do have a few good amp candidates for the job and a spare set of interconnects and speaker cables that could be used. Unfortunately I don't have a crossover or a way to equalize levels, but just setting up biamping without those things might be enough to let me know if I'm getting in the ballpark.

I tend to agree, RJ, it very well could just be old output tubes. I've read the P5s tend to be rough on them and Homer didn't really know how many hours were actually on them. There's a hodge podge of different brands, and I added a few more brands to the collection. It currently has EH, Mullard RI, SED Winged C, and JJ EL34s in it. The input section tubes look to have been replaced when the cap job was done as they are newer EH gold pin tubes. However, NOS 6FQ7 are still pretty cheap as are the 5751s. I also may have some of each in my stash, so that would be an easy thing to try.

I hear you on vintage setups, AJ. This issue seems to go beyond the vintage piece though. I have a set of home built 2A3 amps that have better bass, and that makes about zero sense when you're comparing a 1930s amp design that has 3wpc to a 1980s design with 200wpc. Grant it I don't run the 2A3s on the MLs, but it shouldn't really matter. I've also had SE EL34 amps before that had better bass. Even my Quicksilver GLA with EL34s from a similar era as the P5s had better bass. Something definitely seems amiss.

I did some perusing of the schematic to see if there was anything that screamed at me that could be a culprit, or if there may be some simple mods I could do to experiment. The schematic is a rather interesting design in that it uses parallel plates on the 6FQ7s as a phase splitter. I've never seen a phase splitter design like that. Also, it uses a fair amount of global negative feedback that connected to the 16 ohm tap on the output transformer. An easy test would be to move the negative feedback from the 16 ohm tap to the 8 ohm tap. Not something I'm considering anytime soon. I think such things would be after new output tubes.

Thanks for sharing the Moscode 600 review AJ! After getting the P5s, I'm amazed at how well the Moscode competes. As I've stated, the Moscode definitely has better bass, and it's not really close. The highs are similar with the Moscode but not quite as refined as the P5s, and the P5s sound a bit more lifelike in the midrange. That said, the P5s may pull away more once I get them dialed in a bit. Plus my system is currently optimized for the Moscode, so there may be a need to optimize cables, etc, for the P5s.

I plan to listen some more tonight and perhaps try a few tweaks and / or roll input tubes.

boxcar

[Boxcar]

I’m assuming your speakers are the ascent - i, introduced in 2003.

According to the manual, there is a bass contour switch on the terminal block, labeled, so you could try that for free too.

And do take care to get the speaker wires phase coordinated so that one speaker’s low frequency output doesn’t cancel the other.

You’ve probably already got a copy of the manual. Martin Logan speaker manuals have historically been among the very best. There are several trouble shooting suggestions.

Thanks, AJ. Yes, I do have a copy of the manual for My Ascent speakers. I have the bass switch in the flat position (not -3dB). I have the Ascents a good 3 1/2 feet from the back wall and 3 1/2 feet or more from the side walls, so I don't get a lot room enhancement for the bass. Plus the back of my listening room is open into the dining room and kitchen area, so the bass sounds better with it in the flat position

I did a modification to the cross over on the MLs a while back that really seemed to help. On the Ascent crossover, ML used a large 30uf Solen cap as a high pass filter on the panels. After reading how people would modify their Quads to take out the big electrolytic caps Quad used as an HPF to protect the panels and replaced them with film caps, I thought I would upgrade the Solens. I used Jantzen Superiors from Parts Express. Jantzen doesn't make a 30uf Superior cap so I had to use 2x 15uf per speaker. I was amazed at how much improvement it made to the sound of the panels. Not exactly a cheap upgrade at about $200 / speaker, but well worth it way more cost effective than upgrading to a different ML.

The modified hybrid Moscode is definitely a different animal, and you like it. On speakers like the ascent-i, the impedance can dip to very low values, and when this happens, the speaker cables become even more important because their impedance can become a greater percentage of the total load. So speaker cables may be a place to look.

There could also be some synergy between your modified Moscode hybrid and your preamp that is not replicated with the P5, or perhaps worse, the P5 may not be a good match for your preamp.

There’s just a lot of stuff in play here.

While we all respect BT and his reputation for careful work, the P5s are modded too, and that makes it harder to speculate about pairings.

I’m sure you’ll figure it out. Lucky for you that your girlfriend wouldn’t go along with abandoning the NYAL gear.

Edit: I see you’ve got a PV5 preamp. It should be a good match for the P5, although the CJ hope was that you would purchase a Premier preamp too ().

The real fly in the speculation ointment is that you like the modified hybrid NYAL Moscode.

If I were doing my Harvey Rosenberg impression, I’d say “It is as God intended. I have spoken.”

For those who don’t remember NYAL, the Moscode 600 is reviewed on p 82 of this issue of stereophile. I think Anthony Cordesman was the reviewer.

https://worldradiohistory.com/Archive-A ... 8-No-5.pdf

The PV5 / Moscode has been a great combo. I had a guy I met on the internet that contacted me when he found a Moscode 600 at a very good price (like $400). I told him to jump on it. About 3 months later, he contacted me again and said he found a PV5 for $300. I told him if he didn't buy it, I would. I think he was finding this stuff at these prices at estate auctions. He tried them together and really loved them, too. Unfortunately his Moscode died a few months afterwards and I don't think he's had it fixed yet.

You're right! Good thing that my girlfriend wouldn't support getting rid of the Moscode!

And yes, you're right, the "right" preamp to have for the P5s would be a Premier 3. Truthfully, there's not a lot of difference between the PV5 and the P3 preamps circuitwise, although I've never heard them side by side to compare.

More to come

boxcar

[AnotherJohnson]

I think the real proof here is that you have better sound with the modified hybrid Moscode, and that shows that better sound is possible.

My guess is that these P5s have found a home where they may be tweaked back up to snuff by your good efforts.

There are a lot of ways to approach this hobby, all of them equally valid. These amps have found their way to you … and you’ll have fun making them your own.

Best of luck!

[Merak]

I too recently purchased a set of Premier 5s and had the same reaction as Boxcar: very lush midrange, muffled highs and ill-defined bass. General lack of drive and transparency. Fortunately the seller had told me he'd take them back if I didn't care for them, and he was a gentleman of his word. I later mentioned this to Bill Thallman who replied that the output tubes must have needed replacing (they had the correct Svetlana "Winged Cs" in them). A full retube is an expensive proposition for amps this old when you have no idea whether they really will sound good at the end of the day. I wonder if CJ preamps of this era were simply better than the amps - my PV9 sounds magnificent.

[AnotherJohnson]

I too recently purchased a set of Premier 5s and had the same reaction as Boxcar: very lush midrange, muffled highs and ill-defined bass. General lack of drive and transparency. Fortunately the seller had told me he'd take them back if I didn't care for them, and he was a gentleman of his word. I later mentioned this to Bill Thallman who replied that the output tubes must have needed replacing (they had the correct Svetlana "Winged Cs" in them). A full retube is an expensive proposition for amps this old when you have no idea whether they really will sound good at the end of the day. I wonder if CJ preamps of this era were simply better than the amps - my PV9 sounds magnificent.

The amps sounded mushy to me back in the day.
Both the amps and the preamps sound vintage to me today.

The pairing of tube preamp with SS amp was a good pairing in those days. I used a PV5 with an Electron Kinetics Eagle 2A myself.

The less well defined low end is really the driving force behind biamping a tube top with an SS bottom.

After many experiments, I think the whole business is misguided but fun. It gives the experimenter a sense of purpose and a goal.

Better to just fork over the bucks for a good modern amp.

When people comment that “That tube amp sounds like solid state.” (which is often meant as a negative comment), what they’re really observing is that that tube amp can actually handle bass with authority. 21st century tube amps from CJ can deliver the goods.

As for the PV preamps, they sound like music … but in direct comparison to modern CJ offerings, it is clear that the PV units are veiled. You’ll never notice if you don’t do the direct comparison. Once again comparison is the author of dissatisfaction.

[AnotherJohnson]

Some other pairings I enjoyed in those days …

PV8 and MF2200. I sent the PV 8 in for the Teflon cap upgrade. Sonically it was a good move. But it made no economic sense. Better to move on.

PV11 and assorted Krell and CJ solid state amps in various biamped configurations. These systems were quite nice if not compared to current models.

[AnotherJohnson]

A Premier 5 review by JGH from 1985 I think, but republished in 2009.

https://www.stereophile.com/tubepoweram ... index.html

Of course boxcar’s have been hot rodded by BT, so Gordon’s assessment isn’t definitive … just of potential historical interest.

[petertg]

If you are using the 16 ohm output tap with ML Ascent speakers that is clearly a mistake! CJ recommends the 4 ohm tap for use with most speakers.

[Big Dog RJ]

Yes, that's correct! That's the very reason why CJ in their later amplifiers were factory set at 4 Ohm loads. This presented higher current, including higher stable voltage, better designed power supplies and a higher Class A bias, according to LJ and Ed... so there's a reason they did this.

As an additional option, if the user really wanted to connect highly efficient speakers then CJ would rewire things for either 8 or 16 Ohms if the user wishes. However, factory set for 4 Ohms was a much better performance overall.

I hope Boxcar was not using the 16 Ohm taps... mmm
You need to check that Bx-C!

Best, RJ

[shark23235]

I saw a picture of these amps being used with Apogee speakers, not sure which model but they were known to drop down in the 1-2ohm range ... depending on model. I would guess the amps are setup for 4ohm. Ya never know though.

[admin]

We should also remember that the resistance of speakers are not actually constant with play. There can be significant fluctuations depending on frequency variation. The ability to drive the speakers adequately during these variances is often what separates the "good from the bad" amps.

[Big Dog RJ]

Attn: Boxcar!

Did you check on which output taps you've connected your ML stats to?
The older versions of the Prem5a monoblocks had 3 screw type outputs, which were quite annoying... so many of these screw type outputs were modded to have just a single pair of outputs ( as is the case done on many mods now), and hopefully this has been set for 4 Ohms...?

If not, you need to use the 4 Ohm taps and nothing else mate!

Let us know what you come up with.
Best, RJ

[Boxcar]

Greetings CJO Brethren!

Long time no talk. My apologies. I grew so frustrated with the Premier 5s that I boxed them back up and stuck them into storage hoping that perhaps in a year or so I would find the courage to try them again, perhaps with some other system changes. I'm slowly getting to the point of trying them again.

To answer one of the (still open) questions: Bill Thalman converted the amps to have 4 binding posts on each amp, one for ground and then 4, 8, 16 ohms. I've been running them at 4 ohms with my MLs. Anything else would probably fry them lol!

A year ago, the tube situation was a complete nightmare. Prices have been coming down. Not a ton, but they're better. I could buy all PS Vane EL34s for the Premier 5s for less than $450 right now. They would have cost me $800 a year ago. Not sure how good the cheapest PS Vane tubes are, but something I've been considering.

Recently I attended AXPONA here in Chicago. Always a fantastic time! Unfortunately, CJ gear is extremely scarce at AXPONA. While at AXPONA I bumped into Ralph Karsten of Atma-sphere and relayed my experience with the P5s. He unequivocally stated that I need to get Autoformers. He said tube amps from that era just don't have enough current to drive 'stats without an autoformer. He said that he often would use Autoformers with his OTL amps and 'stats in order to get the speaker load to a point where the OTL could handle it. He recommended the Zero Autoformers that are made by Anticables. He mentioned that with the Autoformers you can use the 16 ohm winding and get much better bass along with better imaging and that the smeared imaging would go away. Sounds intriguing! Has anyone had experience with autoformers and CJ amps or autoformers with electrostats? Anticables offers a 60 day return policy, so it seems essentially obligation free to try them.

On another note, my girlfriend and I recently went to Quintessence Audio in Chicago. They are probably the best hifi store in the city. Mitch and Patrick are great guys! I talked to Mitch (the owner) about the Premier 5s and whether I should replace them or get different speakers and his recommendation was to get different speakers, so I spent the next 3 hours or so auditioning a pair of Sonus Fabers with about $200K of upstream equipment. They sounded nice but surprisingly didn't really blow me away with my current setup with the CJ PV5 preamp and the Moscode 600, which again makes me think maybe I should try the autoformers.

Another thought I've had is converting them to Triode. Supposedly it greatly improves the sound. I'd be curious if the triode conversion is just a standard 100 ohm resistor connecting the screen to the plate while disconnecting the ultralinear lead from the screen or if there's more to it.

Thoughts?

Boxcar

[admin]

Interesting view about the autotransformers. I've never used one and I too wonder if there would be of any benefit with my maggies? It's a fairly expensive option so I would definitely want to make sure it improves the sound prior to committing to the purchase.

[AnotherJohnson]

Since you are already on record as liking the OTL Futterman amps, we’re obviously not on the same page hearing wise.

Suffice it to say that I would strongly recommend AGAINST this idea. In my opinion, it is fatally flawed.

But … your ears, your money, your time, your system.

[Big Dog RJ]

Yep, agree with AJ on that. Autoformers... mmm well that's a whole different discussion I really don't want to go into.
I would say though, they're more suited towards horn type speakers. Very easy load and high efficiency.

"Older CJ amps" not being able to drive difficult loads... uh?
It was in fact those earlier models; Prem1 to Prem5 and the newer versions of those Premier series 11A, 12 and 8A bring about the best in power amplification of its time!
They were fitted with what's referred to as "stiff power supplies." These are very high current design with highly stable voltage.

Tubes are high voltage devices with low current and high impedences. So in order to drive speakers effectively, Output trannies were used to generate the required high current and for impedence matching. In turn the Output stage consisted of either EL34's or 6550's at the time, and were connected in such a way, they were direct coupled to the driver/ phase inverter stages. Nothing in-between, so this direct drive from the Output stage is perfect to handle difficult loads.

In order to handle electrostats or ribbon panels effectively, you need high voltage. That's what drives these types of speakers. The voltage can sway if the amplifiers cannot maintain or produce high current. Therefore, getting back to basics, power = V x I (voltage x amperage). If these V and I ratings are high and are very stable, then the overall power ratings of that output stage won't falter even under stress.

Most so called power amps crap themselves simply because one of these elements ran out of puff. Either the amp's output stage wasn't capable of generating high enough voltage, so the current suffers and power drops and vice versa.

Well designed tube amps are the very essence of high power, high current and high voltage, so they have absolutely no issues driving difficult loads. However, not all tube amps are designed with rock solid power supplies. Few brands to choose from: CJ, ARC, VTL, Manley Labs, VAC, Jadis, Ayon, Destination Audio, Kondo Audio Note, and Lamm are those with very well designed output stages. Their power supplies don't flinch one bit!

As the decades went by and CJ, ARC, VTL and the others, further refined their power supplies to such an affect, that now you have not only very high current and highly stable voltage designs but also fast and quick responsive power supplies that are both highly efficient and musical at the same time, not just brute force like their vintage models.

So some chap telling you that older CJ gear can't drive stats... load of bollocks!
In all my previous systems that I put together for customers during our dealership years, the most difficult to drive speakers, such as Apogee's, Infinity's, VMPS, Dunlevy and Thiel's were always matched with either CJ, ARC, VTL or Melos amplifiers. These were all tube design and had zero issues driving these types of speakers. Of course on SS, there were others, Krell, Bryston, Class'e, McIntosh etc.

I sincerely believe that the comment made about older tube gear with trannies not being able to drive stats, was more to do with a marketing spin, trying to get you onto different amps. As rightly pointed out above, your choice, your decision... All the best!

Note: converting to Triode mode will further reduce the amps output power, why on earth would you do that! The Ultra linear mode is the most efficient config used in high powered tube designs. This is now the standard unless you wanted SET on very efficient speakers, Horns, stacked horns or horn loaded designs. Again, why mess with UL?

RJ

[Big Dog RJ]

I was just reading through your initial posts, and understood that you've got the Prem5's already upgraded with Teflons and it was a huge improvement... according to you.
Then you want to further change things because you feel something is lacking... or thinks something is lacking.

Mate, to be honest, I think you don't know what it is you're after. First you have to decide that! You have to have a reference point... this can come from either a type of recording, a live performance or even someone else's very highend system or some system in a dealership, where that type of sound is your reference point.

At this stage, I don't think you've got a reference point... hence you're going in circles. Therefore, I'm out of here, I can't further comment simply because you don't know what it is you're after!

Hope you understand what I'm saying, I say things very direct, and I don't sugar coat.

One thing certain is that your audiophile girlfriend knows exactly what type of sound she likes. Good on her! She has a reference point.

All the best in your Audio journey.
RJ

[AnotherJohnson]

RJ is on target.

Stat panels were made for those period correct tube amps. ARC and Maggie were joined at the hip.

Whatever else this guy told you, save some time and forget all of it.

[Big Dog RJ]

If I gave those amps to my techie, oh boy! Would he make them perform like no other! Going through the OP's earlier posts, something is lacking compared to his preferred amp. That being said, says they lack pace, rhythm and timing or something to that effect. Which means, no sparkle, dull sound, hardly any defined bass and fluffy mids... this is an Output stage issue. I would do a full tube replacement (output ,input & driver tubes) do a full rebias and adjust spec, run the amps for extended periods non-stop, allow the caps to nicely settle in. Run the amps over a period of 3 to 4 months and then evaluate. Of course don't run the amps non-stop for 3 - 4 months, you'll burn out the bloody tubes! Just 4 to 6hrs a day... over a period of time.

These aren't ordinary amps, these are the Premier 5, built with very high tolerances during their time. I know these amps well and this was one combination that could drive my previous Infinity's IRS 1B's really well. So these not having pace rhythm and timing... is definitely not upto spec!

Something requires attention and I would look into All the tubes, not just the output tubes.
Hope it goes well or maybe just return the amps to Homer dk. Maybe the Prem5's aren't your type of amp... just saying, I really don't know what's going on here.

The other thing is, when it comes to owning large monoblocks, be prepared to have plenty of cash for tube maintenance... if not, then just stick with SS

Best, RJ