Solid State Confessions

Gary-you mentioned this to me before and the idea sounds very good. What doesn't sound good is trying to keep two Defy 7 amps running and in tubes. Now we would be talking about $1,600 to retube the amps and that cost will never go away and willl probably go up. I do think the secret to the Jadis amps is their output transformers. They are works of art and they are massive. The output transformers on the Defy 7 look like they belong on a 300 watt amp. I assume the Defy 7 is mainly Class A because of having 6 KT-88 tubes per channel and only claiming to have 100 watts of output power. Most tube amps that had 6 KT-88s per channel would be rated for at least 200 watts per channel.

The Defy 7 is class AB. Do not give-up on it, it is and excellent amplifier. I used mine with SED 6550c , that cost me around usd 600 for a complete re-tubing in europe. Did you ever listen to it using the matching JPL preamplifier? I do no doubt that your Counterpoint is a very good preamplifier, but I only realized how good the Defy 7 was when I matched the two.
 
microstrip-I don't think it matters with regards to push-pull or parallel single-ended. The point holds true for either type of amp. You are never going to get two output tubes to match perfectly, let alone 12. I am dealling with 6 per channel. I buy the best tubes I can and as matched as they can be. They are not perfectly matched. They are just *close.*

My point is that having 12 equal tubes is not necessary in your Jadis. They should be reasonably close in current matching in sets of 3, and the sums of the transconductance of each set of 3 should be approximately the same as the opposite set. If you get the 12 tubes all matched for current and gm, you are safe.
 
Lower noise floor = less masking, better resolution of the subtlest details at lower volume. It's no surprise that the Phase Linear does this well. I wouldn't be surprised if that cymbal was clearer as the volume comes up, too. Clipping and metal tweeters make harsh bedfellows. What you're hearing is headroom. An amp that can drive your speakers hard without even getting up out of its chair. In my view, there can't be too much headroom, and there really is no substitute for it. The only question in my mind is what was wrong with the Pass Labs?

Welcome to the dark side. Next up? Active. Bwahahahahaha!!!!!!!!!!!!!!!!!!!! ;)
Tim

Tim-All I can say is the guy I sold it to never said a word to me after the sale. I also didn't like the ARC LS-17 and the guy I sold it to kept sending me emails telling me how great the preamp was. Go figure.

Tim, my speakers are very efficient and should be a fairly easy load for any amp. I don't think I am hearing headroom issues. The Jadis is very powerful. 6 KT-88 tubes per channel will do that for you. The Phase Linear has twice the power, but as we know, that only translates into another 3dB of sound output. I certainly agree with you that you can never have enough headroom. Hell, maybe I will end up with a pair of McIntosh 501 amps. I'm just a little humbled right now. It's not over yet. I will listen tonight and gather some more information. I just can't believe that I'm seriously comparing an old Phase Linear amp to a Jadis amp.

As for the Phase Linear 400 Series Two amp, I believe that Bob Carver left Phase Linear before the Series Two version of the amp came out. The original 400 amp had VU meters and slightly different circuitry. The Series Two replaced the VU meters with red LEDs. When Bob Carver brought out his first amp under the Carver name, I believe it was the C-500. It looked very much like the Phase Linear 400 Series Two. It even used the same LED meters. A friend of mine when I lived in Maine had that Carver amp and I always liked it. It was very fast sounding, and it was great as a sub amp. We used to take turns going to each other's houses every weekend and we always brought gear over to each other's houses in order to make our stereos sound as good as possible. My friend always brought the Carver amp and we used it to drive my transmission line subs. When I went to his house, I always brought my Counterpoint 5.1 preamp in order to elevate his system.
 
The Defy 7 is class AB. Do not give-up on it, it is and excellent amplifier. I used mine with SED 6550c , that cost me around usd 600 for a complete re-tubing in europe. Did you ever listen to it using the matching JPL preamplifier? I do no doubt that your Counterpoint is a very good preamplifier, but I only realized how good the Defy 7 was when I matched the two.

I bought the Jadis from the original owner. He bought it from Brooks Berdan and they took care of the amp for him. He wouldn't bias it himself. He always took it to Brooks Berdan and had them do it. What a pain in the ass that must have been. The amp arrived to me in the original box with all the original packing material and everything this amp ever came with. It looked brand new when I took it out of the box. This guy took super good care of his gear. When I first bought the amp, it came with a tube set from RAM Labs. The output tubes were the SED 6550s which I used until last June when a couple of them went south. I went for the GL reissue KT-88s based on positive comments from lots of people including the owner of Jadis who I was communicating with before I bought the new tubes. And if the Jadis Defy 7 is a class A/B amp, how come it only puts out 100 watts per channel with 6 KT-88s per channel? It has to be heavily biased into Class A otherwise, this would be at least a 200 watt amp (which it sounds like by the way).

I'm not giving up yet and maybe soon I will regret even starting this thread. I'm just a little shaken right now.
 
Steve, what's your motto? Isn't it something to the effect: am I hearing something that is better or I am just hearing something that is different?
 
Although it is not clear for me if your are addressing pushpull amplifiers or paralleling several tubes to get a composite tube with lower plate resistance and higher current capability, I should refer that paralleling tubes per si is not a bad thing. We have two important parameters in power tubes - plate current versus bias voltage and transconductance. If you select and match the tubes you can get a composite tube with very good characteristics. Each of my VTLs have 12 6550C tubes - I select them in a way that the sum of the tranconductances of the push side
equals the one of the pull side.
Match pair in pushpull is more important than SE. even parallel in SE still only single one still better than two of them if they can have same power out put, at least lower the cost, my transmitting tube 805 NOS stuff, do not have the re-tube problem, I think they can last longer than my lifetime because they were designed in CCS on military and industrial grade but we only use 1/2 of it's ICAS standard
 
Tim, my speakers are very efficient and should be a fairly easy load for any amp. I don't think I am hearing headroom issues. The Jadis is very powerful. 6 KT-88 tubes per channel will do that for you. The Phase Linear has twice the power, but as we know, that only translates into another 3dB of sound output. I certainly agree with you that you can never have enough headroom. Hell, maybe I will end up with a pair of McIntosh 501 amps. I'm just a little humbled right now. It's not over yet. I will listen tonight and gather some more information. I just can't believe that I'm seriously comparing an old Phase Linear amp to a Jadis amp.

You're right, Mark, that was a knee-jerk reaction to tubes not to that specific amp. Call it expectation bias! So, you've got a big, hefty tube amp that sounds good, and you've got a big heft vintage SS amp that sounds good. No need to be humbled; you've just discovered that it's all good. No need to be very surprised either. Bob Carver was pretty brilliant. In any case, it sounds like you're having fun.

Tim
 
You're right, Mark, that was a knee-jerk reaction to tubes not to that specific amp. Call it expectation bias! So, you've got a big, hefty tube amp that sounds good, and you've got a big heft vintage SS amp that sounds good. No need to be humbled; you've just discovered that it's all good. No need to be very surprised either. Bob Carver was pretty brilliant. In any case, it sounds like you're having fun.

Tim

Tim-The Phase Linear 400 Series Two amp is not really big or hefty. I can carry it with one hand. The power output is hefty though. And I do believe that Bob Carver is a very smart and talented engineer. After the C-500 amp, Bob came out with his line of magnetic power supply amps that I was never fond of. Remember the first Carver Cube amp? The C-500 amp represented the last amp that Carver designed with a *regular* power supply that used a common type of power transformer.

The Jadis new was around $8K I think. I paid $2600 to the original owner and was damn glad at that price and condition. I don't know what the Phase Linear amp sold for new. I paid $385 for mine, and that was a little high, but mine had just been gone through by a really good tech and the filter caps were replaced and the amp works perfect. That was worth a little more money in my book. I just can't believe that I'm comparing the two. Normally I would be turning up my nose right about now.
 
Tim-The Phase Linear 400 Series Two amp is not really big or hefty. I can carry it with one hand. The power output is hefty though. And I do believe that Bob Carver is a very smart and talented engineer. After the C-500 amp, Bob came out with his line of magnetic power supply amps that I was never fond of. Remember the first Carver Cube amp? The C-500 amp represented the last amp that Carver designed with a *regular* power supply that used a common type of power transformer.

The Jadis new was around $8K I think. I paid $2600 to the original owner and was damn glad at that price and condition. I don't know what the Phase Linear amp sold for new. I paid $385 for mine, and that was a little high, but mine had just been gone through by a really good tech and the filter caps were replaced and the amp works perfect. That was worth a little more money in my book. I just can't believe that I'm comparing the two. Normally I would be turning up my nose right about now.

For the record, when I say big and hefty, regarding an amp, I'm talking about performance not weight and mass. How much water an amp would displace in my bathtub is of absolutely no interest. I have 325 watts of bi-amp inside each speaker cabinet. They're A/B, quite small and deliver a wallup of sonic girth.

For what it's worth, I don't put a lot of weight in $2600 vs $385. It ain't about money. Congratulations on your catharsis. I suspect you'll get back to your big tube amp soon enough, but you'll have a whole new perspective when you do. Always a good thing.

Tim
 
In 1975 I had a Phase Linear 400 driving dual Large Advents, with a Phase Linear 4000 pre-amp (remember the Auto-Correlator?) My first "hifi" system.
 
Headroom is the secret of life. There should be enough headroom in those two amps with the sensitivity of those speakers that, operating at moderate volume levels, the audible differences between them should be negligible. If not, then either A) one of them does not have as much headroom as its ratings would imply or B) Somebody has designed for something other than a flat frequency response.

Tim
 
Headroom is the secret of life.
Tim

Tim,

I although had this idea. But many years ago I got a CD test with a 1KHz track at -40 dB and when I played it at the maximum volume settings I use in my system and measured the output voltage I found the measured value was less then 1/100 maximum voltage levels bellow clipping of any of my power amplifiers ... Typically the power peals were less than one fifth of the maximum power.

So I discarded headroom as one of my problems.
 
Steve, what's your motto? Isn't it something to the effect: am I hearing something that is better or I am just hearing something that is different?

that's my mantra in this hobby.

"Did I hear something better or just something different"
 
Headroom is the secret of life. There should be enough headroom in those two amps with the sensitivity of those speakers that, operating at moderate volume levels, the audible differences between them should be negligible. If not, then either A) one of them does not have as much headroom as its ratings would imply or B) Somebody has designed for something other than a flat frequency response.

Tim

C) They have different distortion spectra

This is a metric that is starting to show up in manufacturers specs and accounts for audible differences outside of plain jane FR and output ratings :)
 
Steve-And that's where I'm at right now. I definitely hear something different, but I'm trying to decide if I'm hearing something better. There is no doubt the bottom end is better. I have had other SS amps in my system before. The best one was the Symphonic Line amp. And that would be the real Symphonic Line amp made in Germany. At the time, it was the best SS amp I had ever heard, but I still was glad to get it out of my system and go back to tubes. And that is usually the way it goes. I guess I would feel better about this if the SS amp was some fairly recent design from a snooty brand that people fawned over. This is making me question my belief system and I may be asked to turn in my audiophile creds before this is over.

I put the Jadis back into the system last night and it's working perfect. After about an hour, I pulled it out and put the Flame Linear back in because I wanted to hear it. That just never happens at my house. I have had back up SS amps before and I sold them because I knew that I disliked their sound so much I wouldn't listen to them even if my primary amp broke down. One of those was an older McIntosh amp. I just got honest with myself and said what good is it to have a back up amp if you hate it and you know you won't listen to it anyway. This is the second time I have pressed the 400 into service. The first time was memorable. I remember writing an email to Myles and telling him the damn thing sounded pretty good. Even though Myles was in NY, I could tell he was looking at me to see if I had grown a tail. Call me conflicted at the moment.
 
In 1975 I had a Phase Linear 400 driving dual Large Advents, with a Phase Linear 4000 pre-amp (remember the Auto-Correlator?) My first "hifi" system.

A friend of mine had the Carver C-4000 Auto Correlator preamp and it was dreadful. The over-achieving NAD 3020A used as a preamp only was much the better sounding. It didn't look as cool, but it sure sounded better. I assume your 400 was the first one with the VU meters?
 
I have to add that for me the conflict between solid state and tube electronics has been for a long time a question of value for money or opportunity. Most of my gear was bought second hand - why pay more to suffer the break-in phase :eek: - and the offer of quality products for nice prices was much better in tube equipments. Also, serviceability of used equipment, no more under warranty, was much less critical for tubes than that of solid state. I could happily deal myself with the eventual problem of the cj's, ARC's and Jadis's, but looking at the Electrocompaniet, Levinson or Krell pcb's would be behind my patience.

I also found that when using solid state getting a synergistic system was critical - usually you could not mix brands, and speaker choice was also more critical. I still think that the best solid state system I heard was a Levinson ML31.5 - ML30.5 - ML380s - ML20.6 with Transparent top cables, the whole system surpassed any of the components.

Even today I consider that the current ARC tubed gear is good value for money - just look at the prices of the rivals. But, as I stated elsewhere, I am really curious to listen to the new Classe M600's.
 
To add another wrinkle to this Shar-Pei puzzle, I was trying to think about what has changed in my system that would now make a SS amp sound so appealing (although mind you, I did cast an inquisitive eye on the 400 the first time I pressed it into service). The only thing I can think of is my Counterpoint SA-5.1 has only been back at my house for two weeks since it came back from having the power supply rebuilt and the volume pot was replaced with a DACT attenuator. I haven’t really wrapped my head around what changes to the sound I detect from the latest upgrades to the 5.1. It just sounds very neutral to me without calling attention to itself or any part of the frequency spectrum which is as it should be.

Maybe it’s just a coincidence of timing, but in the last few weeks there seems to have been some type of convergence going on where all of my sources are now sounding really good. I attributed the vast improvement in my digital sound to using Foobar instead of Media Monkey. My LPs and R2R tapes always sounded outstanding before. There used to be a clear pecking order to sound quality in my system:
1. 15 ips 2 track tapes
2. LPs
3. Digital (and this was a very lagging third place mind you)

The order still hasn’t changed, but the gap between second and third place has closed quite a bit. And trust me, I ‘m not spoiling for an analog/digital food fight here. This is just my preference and surely not the preference of those who solely love the digits. I am trying to make my digital sound better and it has come a long way in the last couple of weeks and that makes me very happy. I have a fair amount of money invested in my digital music and I always felt it was a shame I didn’t want to listen to it. Now I do.
 
A friend of mine had the Carver C-4000 Auto Correlator preamp and it was dreadful. The over-achieving NAD 3020A used as a preamp only was much the better sounding. It didn't look as cool, but it sure sounded better. I assume your 400 was the first one with the VU meters?

Yes, with the VU meters. The Auto Correlator was awful, but of course it could be switched in or out. That pre-amp only lasted a couple of months, I traded it in on a modified AR-3a which I kept for many years.
 

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