Classic 60SE tube Question

[jahatl513]

Hey all, on the Classic 60SE it came with KT120's and I wonder what other tubes work well or best for those who have it; any other ideas as well.

[mgttr]

I have a Classic 60SE and was not aware that any tube could be substituted for the KT120? I think it sounds fantastic as is. My unit has Tung-Sol KT120, and Gold Lion 12AU7 and 6922, all purchased from Upscale Audio. I have experimented with using a NOS 6189 (which I believe was the OEM tube from CJ - for the 6922 I believe CJ used Electro-Harmonix) in place of the Gold Lion 12AU7, and found that I preferred the sound of the Gold Lion tube. I have not played with different 6922 tubes as I am really happy with the sound with the Gold Lion tubes. The Gold Lions are new production, so they don't cost an arm and a leg as some of the exotic NOS options.

[roberto]

Hola,

The KT-120 is the new tube, having the same characteristics of the 6550 and it has more power dissipation and more plate voltage capability. In other words, better specifications. You can replace a 6550 for a KT120. Having the KT-120 better specifications, only another KT-120 can replace it.

I am a KT120 user and I love it. It owns the sweetness and warmth sound of the EL34/6CA7, and it has a kick. well controlled, deep bass with a wide stage, providing the right size of the musical instruments. The timbre of the metals is ousting with very good dynamics. Great sense of 3D. It has a midrange with an inner detail with tons of great harmonic texture. The transparency is very evident, crystal clear highs, where you can hear if the drummer is using at the stick end, ( Quality Of Silence by Steve Davis DSD ) nylon or wood. Women voices are projected with outstanding realism, without any sore throat or hoarseness. I really love this tube.

Happy listening!

[mgttr]

Roberto, I think you nailed it with your description of the KT-120. I agree with everything you said. To my ear, the KT-120 combines all the strengths of the 6550, KT-88, and EL34. It is indeed a great tube.

[roberto]

Hola mgttr,

I read your seek on tubes. I do recommend for the 6922 the Philips E88CC. This is my favourite. It is quiet, and very well output balanced. My preamp uses only one 6922, and I did try to use different brands. My ears did like the E88CC made by Philips. It is not cheap, but really gives a lot of good sound quality over all.

Happy listening!

[roberto]

Mgttr,

I forgot to mention that CJ use all types of brands on tubes. They have a big inventory and what they do is to test them through to their torture tests, with hight quality goods and listening sessions. Lew Johnson, him self, once told me that.

There are sets of tube brands that suites the CJ quality standards.

Happy listening!

[mgttr]

When I wanted to re-tube my Classic 60SE, I contacted CJ and they wanted $500 for a complete set (they did not tell me what brands they were using). I elected to purchase my tubes from Upscale Audio instead, using the Tung-Sol KT-120, and then Gold Lion new production 12AU7 and 6922. I'm quite happy with the way it sounds and it cost me $375 including tax, which was a great deal cheaper than CJ.

[mgttr]

Speaking of CJ prices for parts and service, I contacted them recently to see what they were offering for upgrades for my PV-12AL preamp (I had noticed it was one of the models they mentioned on their web site as having upgrades available). Their upgrade consisted of nothing more Teflon capacitors, for a mere $1,146! Wow, that's about the same price as I paid for the preamp (used). Those are some pretty pricey capacitors.

[roberto]

Hola mgttr,

You are right! Those parts are expensive, and I assure you that they worth every penny. Quality parts like teflon caps and metal foil resistors made a huge sound benefit on my last preamp. Now I bought an ET-7. I am very happy with it, and this preamp is design with teflon caps.

Quality has no regret! With CJ, you can't go wrong.
Happy listening!

[admin]

I agree, both with being expensive but also worth it. The way I would look at it is like getting your car fixed at the dealership vs local mechanic you've never worked with before. The dealership will cost more, but they will use OEM parts and they are really good at fixing the car as they constantly work on the same 10 models. Nothing wrong with a local mechanic, but it's going to be hit and miss there. You can try to find a local audio guy to do it, but they certainly will not have done that upgrade many times (if at all) in the past. With CJ, you are 100% assured that the job is done and done right. And yes, there is a premium for that.

[mgttr]

I'm having trouble justifying to myself the expenditure of $1,146 on capacitors for my PV-12AL. Is the improvement in sound quality worth it? Is putting a fair amount of money into an older component worth it, versus putting that money toward a new preamp?

I would truly like a preamp with remote volume control, and one that has less gain than my PV-12AL. Between the PV-12AL and my Classic 60SE, I have so much gain that the volume control is barely cracked open at normal listening levels. And naturally, at that low level the channel tracking on the volume control is poor so I have to use the balance control to compensate. I have tried using Rothwell attenuators on the input to the amp, but even with 20 dB attenuation I'm only at 8 to 9 o'clock on the volume control for normal listening!

Also, I'm not entirely happy with the effects of the Rothwell attenuators on the sound (makes things a bit too mellow), but then again without the attenuators the sound is a little on the harsh side, so I don't really know what the best solution is.

[admin]

I can't say whether that much money is worth the upgrade? I think that's a personal choice. Sounds like the gain is really high on your system. The other side we can look at is the speakers. I typically have the opposite issue as my magnepans are very inefficient so I am pushing the PV12 volume dial to about 1 o'clock for moderate listening levels.

Perhaps this gives you a good reason to buy some new inefficient speakers!

[roberto]

Understood your problem.

What you must have is an ET-3SE used, this preamp will love your amp, and comes with a remote control. Each click of the remote will put +- .7dB, so you can adjust the desired level very easy. The letters SE stands for special edition. This model comes with Vishay Metal Foil resistors and Teflon Caps at the critical stages. Believe me, this is a great sounding unit!

https://conradjohnson.com/et3et3se-vacu ... mplifiers/

Happy listening!

[mgttr]

I am running B&W CDM-1NT bookshelf speakers at 88 dB sensitivity - I would call that kind of average sensitivity, not especially high sensitivity. Unfortunately my system is in a smallish office and I don't have the room for Maggies (see attached photo - sorry about the dust and clutter!).

I agree that the ET-3SE looks like a nice unit and has the remote control I'm lusting after, but good grief - it has 25 db of gain which is a lot more than mine at 16.5 dB (and I'm wishing it wasn't even that high). Would I be able to use that preamp with anything but the absolute lowest volume settings?

[roberto]

That's OK. My speakers have 90dB/2.83V/m sensitivity (I think that they do have more). My ET-7, along with the Classic One Twenty SE, are just perfect. My room perhaps is smaller than yours. I am in heaven each time that I do play my music.

Again, each step (+- .7db) is what you get starting from 0 (infinite). The volume used is not a variable resistor. There are relays controlling each step. Each +- .7dB you hear a click. Also, you could change the volume variable resistor for a logarithmic variable resistor. At the beginning of the resistors, it has more resistance than at the end, so you can adjust better the right SLP that you want.

The ET-3SE has the same type of volume control that the ET-7 has. The ET-3SE the right one for your speakers.

[roberto]

Here is what Conrad Johnson says about the volume control: "...Finally, and especially noteworthy, the ET3 features a relay operated discrete stepped attenuator level-control circuit of the type found in the GAT and CT5, absent only the balance control function found in those more costly models..."

[mgttr]

Well I will definitely keep my eye open for a used ET3SE. I have read posts in other forums claiming this preamp eats up tubes quickly. Have you found that to be the case? How much does the Philips E88CC cost that you were recommending in a previous post? I guess if the preamp only has one tube though, you can afford to splurge a bit on it.

[admin]

In the mean time,... and I know this is not the ideal situation, can you increase your listening distance? Every doubling of distance is a 6 db drop in loudness. Sometimes playing with room dynamics can go a long way.

[mgttr]

Sadly no, my listening position is at my desk, so that is pretty much fixed. Something else I have tried is using digital attenuation, by putting in 15 to 20 dB negative headroom adjustment in my Roon Nucleus music server. I believe this is done with 64-bit calculations, so in theory in shouldn't degrade the signal, but I have to say I still don't like what it does to the sound.

[mgttr]

I keep feeling like those Rothwell attentuators just make the sound too dull and they flatten out the dynamics too much. So I’m running another experiment. I took the attenuators out and ran the volume control on the preamp up to the 9 o’clock position, which I figured should get it out of the range where the channel tracking was so bad.

I then delved into the inner workings of Roon once again. This time I left the headroom adjustment off. What I did though is enable DSP volume adjustment in Roon. I left the preamp volume control alone and I used Roon to set the volume. When you enable DSP volume control, Roon gives you a volume slider as well as +/- buttons to click (they adjust the volume by 1 dB each click). This gives me the full range of volume control from my computer (pretty much just as good as the remote volume control I wanted).

Right now I’m at a -27 dB setting, and it’s a very comfortable listening level. I’ve also backed the balance control on the preamp back to the zero setting, which should take some more resistors out of the circuit and theoretically increase the sound quality. So far the sound is pretty good - I will need more time to evaluate it fully though.