New CJ Owner need suggestions

[jimbones]

Hi All, I am new to the group thank you for allowing me to join. I just purchased my first CJ product: Premier 12 monoblocks. The amps sound pretty good but are a bit flat sounding. They are quiet no hums or anything like that. The previous owner supplied some very good brands of tubes: SED Winged C 6550-'s, GE Jan 5751 and RCA Clear Top 6FQ7's. He tested them before he shipped them and confirmed they are good. He seems like a trustworthy guy so all I can think of is that tubes may be old, still test good but do they get "flat" sounding? Needs some jump! Thanks in advance for suggestions

[AnotherJohnson]

Flat compared to what? Describe speakers, interconnects, source and room.

FWIW, It is old. You might be flat too if you were grandfather to as many following generations.

Maybe it needs capacitors.

[admin]

Welcome to CJO. Great to have you with us. Really hard to say. It is an older unit so as AJ notes, it may need a refurb with new caps. I would make sure the tubes are good and not getting to their end of life.

Is there any difference between the left and right channels or pretty much the same?

[jimbones]

left and right are the same. The speakers are a build of the SB Acoustics Rinjani. Interconnects are Transparent Audio, Pre is Rogue RP7 Room is 13x22x7.

[jimbones]

I should also mention my Premier 12 is replacing a SS amp. The SS amp was a bit "hot". My friend tells me that the CJ stuff tends to be tame on the high end so I may need to adjust? I know that different tubes can make a difference. Also when tubes get "worn" do they get dull sounding? Since I should have some spare tubes I was thinking of changing input tubes just to see if it makes a difference

[JoshT289]

I just bought a used Premier 11A, and I use a Rogue Audio RP-5 with it, and it doesn't sound flat to me in any way. My reference amp was a CJ MF2250, which is one of their solid state amps, and it is admittedly anything but hot. To me, the Premier 11A actually livened up the sound compared to the MF2250.

That said, I don't know that the Premier 11A and the Premier 12s are expected to sound similar. I believe I heard somewhere that the Premier 12s might have a darker sound signature than the 11A.

I did decide to upgrade to the C1 Teflon capacitors a month or so after buying the amp used, but that wasn't because the Premier 11A sounded dull or wrong; rather, I liked it so much that I figured I'd optimize it (after CJ first confirmed my amp was in excellent condition).

I think you should try fresh tubes, including the 6550s if they are old. When I put a much newer set of SED winged C 6550s in mine, it did sound brighter than it had with some that were long in the tooth.

[AnotherJohnson]

All good info and advice.

[jimbones]

Flat compared to what? Describe speakers, interconnects, source and room.

FWIW, It is old. You might be flat too if you were grandfather to as many following generations.

Maybe it needs capacitors.

Lol I AM old ha ha. And a bit flat like day old beer.

[AnotherJohnson]

I have never heard those speakers, and I don’t know what sort of load they present.

Are they ported? What nominal impedance do they present? What was the power capability of the old amp?

One thing that can make any tube amp sound flat is the taps chosen on the transformers.

If you’re running from the 16 ohm taps and the speakers are 8 or 4 ohm, that will squeeze the life out of the music.

FWIW, running on the 4 ohm taps will sound the most lively.

Unlike McIntosh, to change the taps on the CJ amps, you have to actually do some rewiring. It’s not hard, and the color code is typically on the transformers.

There are some threads here where this is discussed.

Maybe the guy who sold them to you will know if they were rewired for 8 or 16. As a rule, CJ rates their tube amps for 4 ohm loads, and they ship from the factory on the 4 ohm taps.

[AnotherJohnson]

The color code (posted by Roberto) is here.

https://www.conradjohnsonowners.com/vie ... 500#p10500

[AnotherJohnson]

Are these the speakers?

https://www.madisoundspeakerstore.com/2 ... -kit-pair/

If yes, they appear to be nominally 4 ohms, ported, with 89 dB efficiency.

Your new to you CJ amp should easily drive these.

If it were mine, I’d check the transformer taps. That’s free. Then tubes. Last caps.

[roberto]

Hola...just guessing,

If you are coming from SS sound, the apparent sound quality of the tubes is kinda dull, but the truth it is not. Have you noticed that the drummer is at the back of your virtual stage? Also cymbals are located there, where the drummer is located usually. Also, the main artist is forward center, in other words, you do have a sense of 3D, and your seating position at the event is circa at the middle of the room. With SS you are usually seating at the very first center rod.

The brightness exhibit with SS is totally different than of the tube. You have to get accustomed to the tube sound. Once your ears start to understand this new quality sound, there is no go back to SS.

Tubes are not too bright, just enough to play the naturalness of the cymbals and percussion instruments at the back of the stage. This does not means that there is not resolution or the right timbre. Play voices, and feel the air between them. Play small combos, or trios, quartets. Play solo instruments, like piano or guitar. While playing a guitar, you can tell when there are nylon strings or metal strings, right?

That happened to me long time ago. I came from SS and the first thing that I was missing is the brightness. An also understand the stage. With SS, my stage was like a pancake thick. All was there at the front, no sense of 3D.

Just play more music for your ears, and get used to your new improved sound. Tubes have a kind of magic that SS (to my ears) lack. the lower mid-range and the presence of the main artist is the clue. Tubes articulates different the musical instruments. The coherence and the timbre are the things. Once you are accustomed to have less brightness, listen to SS and you will hear of what I am talking about.

Happy listening!

[jimbones]

Yes those are the speakers. Already check the tap is on 4 ohms. I am being picky here so note that I say it is a bit flat, also not as transparent as I would have liked. I am coming from a Wells Audio Innamorata. I have had tube preamps for the last 10 years but this is my first tube power amp. Boy does it kick out heat lol. BTW I checked the bias and it is perfect. turn CCW and the light goes out turn CW and the LED Lights. I think it is the case of the unknown. When you buy preowned even though the tubes are "good" they could degrade in SQ and the only way to know is to replace them with new right?? Im OCD HAAAA

[Big Dog RJ]

G'day JB,

If you're Prem12's are sounding dull or flat, that's a sign of a full tube replacement set. You can start with either the small signal tubes first (input and driver tubes/ phase inverter tubes) and see how things change. Then when you notice that uplift in energy and sparkle, you can change the output tubes. Changing the output tubes to new ones will add further energy and sparkle, like breathing new life into your system.

There should be plenty of drive, power with finesse, transient control, explosive dynamics that are well handled and a tight grip on the speakers. In other words, real effortless drive factor with that superb sense of musicality that CJ is know for.

If you are experiencing "flat & dull" sound, with none of those attributes as mentioned, that's a sign of tube replacement.

If finances permit and you can replace the full set, that would be best. Make a note of the purchase date and you're good to go for at least 2000 to 3000 hours, typically 2 - 3 years depending on average usage. Although the previous owner has included the tubes and checked that the amplifiers are running fine, basically means they're operating without any major issues... only minor issue is that it's not performing optimally as a CJ Premier amplifier.
These are Premier based amplifiers, and CJ's Premier based products are set on high standards, therefore they should not sound flat or dull in any way whatsoever.

As I mentioned, the whole presentation will change and should effortlessly drive those speakers to new levels. If changing the tubes doesn't work then perhaps a cap change or upgrade but that's not a flat or dull sound, that would be very poor sound and distorted stuff coming out from the speakers, it wouldn't be a pleasant thing to listen to.

See how you go and let us know what eventuates. Replace the tubes with the original type that CJ recommends and you should hear a significant improvement.

Cheers, RJ

[AnotherJohnson]

I agree with RJ that, if you’re on the 4 ohm taps, tubes are the next low hanging fruit.

Another thing to consider, if you’ve not already done it, is to replace the tweeters with the Be tweeters that are available as an upgrade for your speakers.

I went this route with my Revels, and although I was happy with the original tweeters, the Be option provided more detail, sparkle, and realism AFTER THEY WERE PROPERLY RUN IN FOR A FEW HUNDRED HOURS.

You might like them too.

Looking over the design of your speakers, they remind me of Jim Thiel’s pioneering work, right down to the Scandinavian sourced drivers.

[Truth71]

Another vote for a new set of tubes.

[roberto]

Hola, and new tubes will make it to sing lovely again. Another vote for new set of tubes too.

Happy listening!