New bee to CJ

[Big Dog RJ]

Yes mate, that's correct!

In fact, I should have known that considering the long dealer network I was once part of. Our good mates in Spore are the main distributors/ importers for CJ (Norman) and they've been supplying to the Sth East Asian region ever since. So their history goes a long way back.

Of course, all my close mates have either retired or gone fishing, must be enjoying those fine tunes!. I do remember them well but back then I was just starting out in the highend. Fast fwd that to 30yrs... memory isn't upto scratch!

If you manage to get in touch with the crew at Norman, and explain what you require, I'm sure they'll be willing to help. Only thing is, you'll have to discuss pricing arrangements and who pays for what and what parts are required for the C1 upgrade. It will cost you a pretty penny.

Few years ago, just before our Covid lockdown in Melb, I managed to get the full SE (C1) upgrade done on my monoblocks, which included Teflon caps and Vishay resistors plus KT120 tubes. Each monoblock cost a pretty penny, however the good thing was that this upgrade was done here by my trusted CJ techie. JF sent him the upgrade kit plus all the tubes, so I was very fortunate to establish that contact. But now, JF does not mail out those kits anymore... unless it was to authorised dealers, such as Norman for example.

So, here's hoping you get in touch with JF, who will point you in the right direction, and get in touch with Norman, who will do the job for you... hopefully! In which case you wouldn't have to ship the amps all the way to the US but maybe to Spore as the final destination. That's not too bad.

Do let us know how it all goes, and keep us posted.
BTW, there's another chap here who got his Prem8A's upgraded to the C1 (SE version) and fitted with KT120's, driving Wilson's X-1 Grand Slams with the GAT preamp, sounds tops, and absolutely loves it!

Cheers, and have a good one now.
RJ

[SolderSlinger]

Due to Teflon capacitor cost increase, CJ changed the C1 upgrade. The larger Teflon caps used in the regulated power supply are no longer included in a C1 upgrade. Consider the current C1 upgrade the "C1 light". It is possible to get the old C1 cap count, but it costs about $160.00 per cap for the power supply. If I had to guess, a C1 upgrade on the Premier 8 will run $2,500/amp for the C1 light. That does not include shipping or a new box.

Alternative to a CJ C1 upgrade is to DIY with Solen Teflon caps. Or consider buying a pair of Premier 8 C1 amps. A CJO member had a pair for sale Sept 2023. I believe he still has them. They were listed on Audio Mart. Good pictures.

https://www.usaudiomart.com/details/650 ... flon-caps/

[gensiva1]

Hi RJ,

Thx again for the inputs and yes I had already got intouch with Norman and also JF replied my email for C1 upgrade $2,500/amp.
I beleive the cost are still same but exluding the shipment. Norman can carry out the job for me alternative I have found a old chap here in Malaysia that does amp refurb for past 40yrs now. Totally, a hided gems but this old person is professional electronic/electrical engineer back in the days that performs repair, refurbishment work for all kind of hifi gears including tube amps. Many review found with his service by satisfied customer with vintage and classic gears that came back alive after his service.

I haven't got his appointment yet, I am purchasing all the caps I need. Plan to move with VCaps or Jantzen Audio Superior capacitors.

Power KT120 Tung-Sol or Mullard KT88 / 6550 Vacuum Tubes (https://www.vivatubes.com/new-matched-s ... uum-tubes/)

Any idea if the Mullard tubes are good? For the price its relatively cheap = New Matched Octet (8) is $561.55 -

Great to know someone is out there using Prem 8 with C1 upgrade. Wonder if he can share his experience here...

Cheers, Gen

[gensiva1]

Due to Teflon capacitor cost increase, CJ changed the C1 upgrade. The larger Teflon caps used in the regulated power supply are no longer included in a C1 upgrade. Consider the current C1 upgrade the "C1 light". It is possible to get the old C1 cap count, but it costs about $160.00 per cap for the power supply. If I had to guess, a C1 upgrade on the Premier 8 will run $2,500/amp for the C1 light. That does not include shipping or a new box.

Alternative to a CJ C1 upgrade is to DIY with Solen Teflon caps. Or consider buying a pair of Premier 8 C1 amps. A CJO member had a pair for sale Sept 2023. I believe he still has them. They were listed on Audio Mart. Good pictures.

https://www.usaudiomart.com/details/650 ... flon-caps/

Hello SolderSlinger,
Thx for your feedback here. JF didn't mention to me what includes in the C1 upgrade. Good that you have mention this to me.
However, I have plan to carry out this job DIY with local engineer. I will be buying all the caps (Vcap or Jantzen Audio Superior capacitors) required to be replaced. Only challange is that I need to open to amp to get the cap spec since the diagram we had is not clear.



Thx
Gen

[Big Dog RJ]

Greetings Gen,

Ok that's good to hear, looks like you're on a mission to replace the caps..., make sure you get the right ones, obviously, and the best quality!

Re. To Output tubes: well this is solely based on personal preferences. Nothing else!

The KT120's are a powerful tube, plenty of power with finesse. It has all the great virtues of the EL34's with fantastic midrange and more control in the LF / bass.

The 6550C type is from SED Corp, made in Russia and was widely used by CJ when I owned all three of their Premier line (Prem11A, Prem12's and Prem8A's). It was a wonderful tube with good bass, smooth extended highs and a lush midrange. It was only after I tried out the KT120's in my CJ amps and Manley Labs amplifiers that I preferred the KT120's.

The KT88's have come full circle. These were widely used by Quad and McIntosh back in the day. ARC, Manley Labs, VTL and CJ initially used EL34's and when they started to redesign their tube circuits towards higher power and greater definition, they started using the 6550's and KT120's. However, there are still quite a number of brands that still use the EL34 and KT88, for certain types of applications.

McIntosh still uses the KT88's and so does Quad. And speaking of CJ, their current top of the line- ART series amplifiers happen to use KT88's! So it will depend on how the designer wants that particular amplifier to sound. Also providing options of various types of Output tubes as an owner preference.

It's a bit difficult to try out 16 Output tubes on the Prem8's to determine which type you prefer, hence it's not practical to try 3 different types. The best way of knowing or at least an idea of sound, is to audition these different tube types in other amplifiers in demo systems. All three types are safe to use, it depends on which one you like and your music tastes.

Cheers mate, RJ

[gensiva1]

Greetings Gen,

Ok that's good to hear, looks like you're on a mission to replace the caps..., make sure you get the right ones, obviously, and the best quality!

Re. To Output tubes: well this is solely based on personal preferences. Nothing else!

The KT120's are a powerful tube, plenty of power with finesse. It has all the great virtues of the EL34's with fantastic midrange and more control in the LF / bass.

The 6550C type is from SED Corp, made in Russia and was widely used by CJ when I owned all three of their Premier line (Prem11A, Prem12's and Prem8A's). It was a wonderful tube with good bass, smooth extended highs and a lush midrange. It was only after I tried out the KT120's in my CJ amps and Manley Labs amplifiers that I preferred the KT120's.

The KT88's have come full circle. These were widely used by Quad and McIntosh back in the day. ARC, Manley Labs, VTL and CJ initially used EL34's and when they started to redesign their tube circuits towards higher power and greater definition, they started using the 6550's and KT120's. However, there are still quite a number of brands that still use the EL34 and KT88, for certain types of applications.

McIntosh still uses the KT88's and so does Quad. And speaking of CJ, their current top of the line- ART series amplifiers happen to use KT88's! So it will depend on how the designer wants that particular amplifier to sound. Also providing options of various types of Output tubes as an owner preference.

It's a bit difficult to try out 16 Output tubes on the Prem8's to determine which type you prefer, hence it's not practical to try 3 different types. The best way of knowing or at least an idea of sound, is to audition these different tube types in other amplifiers in demo systems. All three types are safe to use, it depends on which one you like and your music tastes.

Cheers mate, RJ

Hi RJ,

Good day and thx for the experience you have shared on those tubes. It true many claim its preference and some of KT120 comment I read was same as your experience which is much prefed amoung the users on CJ gear 8A with great results.

It will be pain as you mention to try out so I am taking the shared experience from you and others that I have read to try the KT120 in my preparation for upgrade journey.

Its going to cost me some $$

As per the caps I am considering Jantzen Audio Z-Caps. Love to go with V-Caps but looking at the price range for the number of caps to change it will blow up my budget... Jantzen Audio Z-Caps are really good and I have read one review from Italy from one user who had upgraded his Prem 8A with great result.

Will try out for sure but I am trying to upgrade the power section to began with before recap everything else.

This will be long term journey for me

Have good weekend there.

Thx, Gen

[Big Dog RJ]

That's good to hear, looks like you're on a mission
Hope all goes well and just make sure you've got a reputed techie to carry out the work.

Keep us posted on your journey. Those Prem8's should be sounding mighty fine in no time.

Cheers, RJ

[gensiva1]

That's good to hear, looks like you're on a mission
Hope all goes well and just make sure you've got a reputed techie to carry out the work.

Keep us posted on your journey. Those Prem8's should be sounding mighty fine in no time.

Cheers, RJ

Hi RJ,

Thx and surely ensure those point with techie.
I have question to clarify with your expert knowledge.
KT88 tubes works fine with Prem 8A as well and unless the amp has been upgraded caps Kt120 is no go due the spec increase which can cause damage to power supplies due to increase of 30% current and reduce lifespan of caps.

I believe this will becoming together if not I have to stick with KT88 or 6550's until I recap the amps completely to use KT120.

Not sure what is view on KT88 tubes? Appreciate any advise ...
Sourcing tube and found this seller - Upscale Audio sells good tube including a 72-hour burn in process, and testing at real-world voltages.

Cheers,
Gen

[Big Dog RJ]

Yes, understand your question and makes perfect sense.

Originally, the Prem8's were designed for the use of 6550 type Output tubes. At the time of Prem8 and Prem8A introduction, CJ also offered another version called the XS, which came fitted with EL34's. This required a few internal mods on the resistors and was generally done at the factory prior to shipping out to the customer. The XS version was offered solely as a custom order, so the standard was UL pentode 6550's. The EL34's were configured- Triode mode.

During the time of the Prem8A's, this was when CJ gave the go-ahead to use any of the KT series power tubes safely, other than the KT150.

The following can be used with no issues:
Kt88
KT90
KT120
6550

*KT150 * these are quite different from the above and require a higher plate current. Hence, most amplifiers aren't geared to accommodate this higher current draw, therefore the power supplies are limited in their capacity to provide the extra specs required to enable the KT150 into full operation. Same thing goes with the KT170, which requires higher voltage and current specs than all of these types.

So, regarding the Prem8's power supplies and how well designed they are, using KT120's will have no issues.
Upgrading caps is solely for the purpose of replacing old caps, and that's mainly due to the caps being old... or wearing out. Upgrading to either Teflons or other types is fine as this will yield a more luxurious sound or more sophisticated type of sound but it shouldn't affect the use of Output tubes.

If your techie is being cautious about using KT120's... and advises to try either KT88 or 6550's first then that's good advice, since he's being careful. As far as I'm aware and the experience my CJ techie has over here, KT120s have no issues. Their specs are nearly identical to 6550's but higher plate voltages and bias current. Not by a big margin though and when used in circuits base on the 6550's, the KT120's just cruise along. With their higher specs, they can actually outlast the 6550 type.

As an example, the monoblocks I'm currently using are the LP125M. These came fitted with 6550's originally. Over a two year period, I placed in KT120's and got the full SE upgrade done as well, and they sound wonderful!
Before that final step, I also got the chance to try out other tubes as mentioned above, and at the end preferred the KT120's.

Another good mate of mine got the Classic 120se and first tried KT88's, although quite good, his preference were the KT120's so he changed back to this type.

**Note** keep in mind, trying different types of tubes is ok, as long as you're within similar spec and not too many variations. However, it's not a good idea to constantly change... as this can sometimes mess up the bias circuit because of variations in idle current. The main thing is to find one type that you like and just stick with that type. Allowing your amplifiers to nicely settle in properly with the proffered tube of your choice. So don't keep changing.

Hope that helps. There are many others on this forum who have vast experience with tube varieties, perhaps they will also add more insight

Cheers, RJ

[gensiva1]

Yes, understand your question and makes perfect sense.

Originally, the Prem8's were designed for the use of 6550 type Output tubes. At the time of Prem8 and Prem8A introduction, CJ also offered another version called the XS, which came fitted with EL34's. This required a few internal mods on the resistors and was generally done at the factory prior to shipping out to the customer. The XS version was offered solely as a custom order, so the standard was UL pentode 6550's. The EL34's were configured- Triode mode.

During the time of the Prem8A's, this was when CJ gave the go-ahead to use any of the KT series power tubes safely, other than the KT150.

The following can be used with no issues:
Kt88
KT90
KT120
6550

*KT150 * these are quite different from the above and require a higher plate current. Hence, most amplifiers aren't geared to accommodate this higher current draw, therefore the power supplies are limited in their capacity to provide the extra specs required to enable the KT150 into full operation. Same thing goes with the KT170, which requires higher voltage and current specs than all of these types.

So, regarding the Prem8's power supplies and how well designed they are, using KT120's will have no issues.
Upgrading caps is solely for the purpose of replacing old caps, and that's mainly due to the caps being old... or wearing out. Upgrading to either Teflons or other types is fine as this will yield a more luxurious sound or more sophisticated type of sound but it shouldn't affect the use of Output tubes.

If your techie is being cautious about using KT120's... and advises to try either KT88 or 6550's first then that's good advice, since he's being careful. As far as I'm aware and the experience my CJ techie has over here, KT120s have no issues. Their specs are nearly identical to 6550's but higher plate voltages and bias current. Not by a big margin though and when used in circuits base on the 6550's, the KT120's just cruise along. With their higher specs, they can actually outlast the 6550 type.

As an example, the monoblocks I'm currently using are the LP125M. These came fitted with 6550's originally. Over a two year period, I placed in KT120's and got the full SE upgrade done as well, and they sound wonderful!
Before that final step, I also got the chance to try out other tubes as mentioned above, and at the end preferred the KT120's.

Another good mate of mine got the Classic 120se and first tried KT88's, although quite good, his preference were the KT120's so he changed back to this type.

**Note** keep in mind, trying different types of tubes is ok, as long as you're within similar spec and not too many variations. However, it's not a good idea to constantly change... as this can sometimes mess up the bias circuit because of variations in idle current. The main thing is to find one type that you like and just stick with that type. Allowing your amplifiers to nicely settle in properly with the proffered tube of your choice. So don't keep changing.

Hope that helps. There are many others on this forum who have vast experience with tube varieties, perhaps they will also add more insight

Cheers, RJ

Hi RJ,

Thank you again for inside of your experience with tubes on CJ amps. You have point there and did my own matrix with tube spec mention above indeed the spec between 6550 & KT120 not far away. My worries was only heat / current drawn from the tube might damage the transformer, this is only a concern from my own theory but I can be wrong also ...

Even looking at price point both KT88 & KT120 are being very close as well and its tempting to go forward KT120 base on many review I have read where most tube lover settle in with KT120 happily.

My guess I will go another round of read before placing my order soon ..

Cheers
Gen

[gensiva1]

Hi RJ,

Good day and hope weekend was fine for your there.
I had 2 audition with mates over weekend here that was totally different from 1 world to another.

1. was Cary Audio SLP05 with ATC SCM100ASLT with Lumin T2 / Eversolo A6 which was really nice overall.

2. manage to get an appointment from an old gentleman here who owns passive amp, cd player with ALTEC LANSING A5 - never thought I would hear the live music which was so engaging in his gear with tracks from 50's & 60's. Mind blowing...

Good part this gentlemen own a CJ Premier 7B per amp bought brand new 40yrs ago. Still in mint condition fully functional but he is not using them. He has tons of gears that is laying around but not selling sadly - EgglestonWorks Andra 1 , Krell fpb 600, ARC SL5, Marten duke 2.. the list goes on.

I want to get your advise what best suits for CJ Prem 8A, surely going with CJ pre amp will be best since the synergy will be there but alternatively are there any other tube amp that would a good match i.e. BAT VK30SE, Cary Audio SLP05, CAT pre amps?

Any thought RJ.

I like the CJ Premier 7B but downside no remote control but this model was reference pre amp back in the days - I manage to convience the gentleman to sell to me and he offered me (USD4000);

BAT VK30SE comes with both single ended and balance input/outputs & remote and its dual mono construction (USD1900);

Convergent Audio Technology CAT Preamplier SL1 Signature - completely single ended with enternal power supply, no remote (USD2000)

Thought to get your view on this ...

Apprecaite it RJ.

Thx

Cheers,
Gen

[Big Dog RJ]

Those are all fine preamps in their own regard, and will definitely shape the music differently. The one to recommend is the one that "you" like my friend, not me! Therefore, only you can determine that, no one else!

Also, just as a guideline it's better to have the preamp that's more neutral, by not adding too much colorations to the original source signal. There will always be compromises and you'll have to make choices between gear but whichever one that engages you the most, that's the one you'll be most happy with.

Yes, having a CJ preamp in your system partnered with the Prem8's will probably yield the synergy. However, there are other ones that will work just fine, and in certain cases even sound better in your particular system. So you'll have to find the right one that suits your tastes and most of all your budget.

Other members here may also have good suggestions, hopefully they'll make a few recommendations for you.

Cheers mate, have a good one now.
RJ

[SolderSlinger]

@gensiva1
My $0.02 in response to a number of your questions.
I like the Tung Sol 6550 best for driving Quad ESL 2905 or Quad ESL 2805 speakers. Great synergy. Other than the Quads, I agree with others that the KT120 is the obvious choice. Great tube, higher power rating so should last longer, and is only slightly more money than a 6550.

If you are going to replace capacitors use Teflon. If you don't want to use Teflon, then leave the amps stock and use the money for other system improvements. If you look at the schematic section of this forum, download the Premier 8 and Premier 8A schematic. The capacitors that you want to change are the 8 grid capacitors and 4 parallel capacitors near between the input tubes and driver stage. Have the 8 grid capacitors matched as close as possible. Some companies will match to 1%. It's not important to match the 4 parallel capacitors. Most cost effective option I've seen is Teflon capacitors by Solen. Use the following link. It should allow viewing a Solen 0.22uF 1,000V capacitor.

https://partsconnexion.com/products/sol ... 0cc2&_ss=r

I really like a remote control and believe the CJ implementation using relays is the best remote in the industry. I personally use the balance capability of my ET5. Use of balance does not degrade the sound because there is not a second balance pot to affect sound. I use it a lot, especially when running my Diva speakers. Not all recordings are mixed correctly. Off center soundstage recordings bug me. A click or 2 left or right can make a big difference. With that said, consider the ET5, ET7S2, or GATS2.

[Joe Appierto]

SolderSlinger writes:

I like the Tung Sol 6550 best for driving Quad ESL 2905 or Quad ESL 2805 speakers. Great synergy.

I find your comment interesting because when driving Quad 989 speakers I also preferred the Reissue Tung-Sol 6550 as well. The original TS 6550 were in another class but just my 2¢. I liked the TS KT120 just not as much in that application. Generally speaking, the KT120 are well-liked and an excellent go-to choice. Of current production tubes that I tried the Reissue Genalex KT88 were my favorites.

[gensiva1]

Those are all fine preamps in their own regard, and will definitely shape the music differently. The one to recommend is the one that "you" like my friend, not me! Therefore, only you can determine that, no one else!

Also, just as a guideline it's better to have the preamp that's more neutral, by not adding too much colorations to the original source signal. There will always be compromises and you'll have to make choices between gear but whichever one that engages you the most, that's the one you'll be most happy with.

Yes, having a CJ preamp in your system partnered with the Prem8's will probably yield the synergy. However, there are other ones that will work just fine, and in certain cases even sound better in your particular system. So you'll have to find the right one that suits your tastes and most of all your budget.

Other members here may also have good suggestions, hopefully they'll make a few recommendations for you.

Cheers mate, have a good one now.
RJ

Hi RJ,

I agree with your comment. Sometime its a difficult choice but all comes to the taste. I guess I have try it and my preference is to have balance input for source. I have time so will take it easy before getting the correct per amp. Your sharing make me to think more of what I will want and certainly I won't want to add colorations and prefer to keep it original as possible as I can.

Really appreciate it RJ.

Cheers

[gensiva1]

@gensiva1
My $0.02 in response to a number of your questions.
I like the Tung Sol 6550 best for driving Quad ESL 2905 or Quad ESL 2805 speakers. Great synergy. Other than the Quads, I agree with others that the KT120 is the obvious choice. Great tube, higher power rating so should last longer, and is only slightly more money than a 6550.

If you are going to replace capacitors use Teflon. If you don't want to use Teflon, then leave the amps stock and use the money for other system improvements. If you look at the schematic section of this forum, download the Premier 8 and Premier 8A schematic. The capacitors that you want to change are the 8 grid capacitors and 4 parallel capacitors near between the input tubes and driver stage. Have the 8 grid capacitors matched as close as possible. Some companies will match to 1%. It's not important to match the 4 parallel capacitors. Most cost effective option I've seen is Teflon capacitors by Solen. Use the following link. It should allow viewing a Solen 0.22uF 1,000V capacitor.

https://partsconnexion.com/products/sol ... 0cc2&_ss=r

I really like a remote control and believe the CJ implementation using relays is the best remote in the industry. I personally use the balance capability of my ET5. Use of balance does not degrade the sound because there is not a second balance pot to affect sound. I use it a lot, especially when running my Diva speakers. Not all recordings are mixed correctly. Off center soundstage recordings bug me. A click or 2 left or right can make a big difference. With that said, consider the ET5, ET7S2, or GATS2.

Hello SolderSlinger,

Good to meet you and thanks for adding the though for me here. There are few plan on the pipeline for my current setup.
Prem 8A requires new tube soon so I listed KT88 and know seeing many recommendation using KT120 with the stock caps.
Certainly, this given me clear answer as I was worried of using KT120 without the caps being upgraded thinking the amp will get overheated and also reduce caps life due to high current drawn.

I will need to test this KT88 has some good spots and KT120 surely many audiophile favorite.

About the caps the download Premier 8 and Premier 8A schematic are not clear and I have raise this here in the forum and I beleive that the best quality we have. I cannot read the letter, kinda of burl ... unless there is one from someone here who had chance to draw it back.
The only way I wanted to get this info correct was to open the amp and get it right but this will take time for me as the amp is not light in weight for one person to handle.

As you mention for caps input tubes and driver stage and any recommendation for power section? This can be more critical due to the age factor?

Look forward to hear from you.

Thx
Gen