Premier 17 loud pop problem

[sakujou]

Hello everyone,

I apologize the reason for my first post here is to look for help, but I just bought a used Premier 17LS preamp 2 days ago.

The first day I listened to some music, no problems, everything sounds wonderful. The devices were as follows:
Denon CD - > SMSL M8A DAC -> Premier CD input -> Premier Main out -> Lyngdorf SDA 2175 power amp input.
As mentioned - so far so good.

Today I got my AVR hooked up. Connection was as follows:
Denon AVR left and right preouts -> Premier EPL/Theater Input -> Main out -> Lyngdorf power amp input.

As you probably notice I am using the EPL2 input, but not the EPL 2 output, as that would defeat the idea of going through the Premier at all in this case. So going through the EPL2 input and the main output I seem to engage Unity Gain as I get the dashes, instead of volume digits on the Premier's front display and everything works great at first.

Problem is twice already I encountered a VERY loud pop, which by some miracle hasn't yet destroyed my speakers (at least I hope so). I am not sure it could even by considered a "pop" as it it a very, VERY loud noise. Probably close to what my 200W amp could deliver at max, don't know really.

The first time the pop happened my power amp was already on when I tried turning the Premier 17LS on. I am aware usually I should have the power amp off when turning the preamp, but...
Actually it popped when I turned on the voltage switch on ( from 110v to 220v since I live in Europe and the Premier is from USA) and the Premier was still off actually. I thought it might be from the voltage switch, even though I doubt it's at fault. Also thought it might be from the "wrong order" of turning my equipment as I had the power amp on, before the preamp. M

The 2nd loud pop I got when both the preamp and power amp were already on and I tried switching from EPL2 / Theater to Source CD. As soon as I pressed the EPL2 button to return to Source the pop happened.
In this 2nd case I was using the EPL2 input with my AVR for more than 2 hours with no issues. The suddenly sound from the front left and right speakers disappeared and I thought I should test if CD input is working fine, tried switching to CD source and... The above mentioned loud pop happened.

In both cases after the pop my power amps light for "Operate" went from lit to blinking. This prevents it from working. Sometimes it acts up and starts blinking for no apparent reason and I have to restart it. I am not 100 percent sure if in those 2 cases it was already blinking before the pop or it started blinking after the pop. Just wondering if it was blinking already such a state of the power amp could be the cause of the issues with the Premier. But I suspect it is the other way around - first the Premier makes the speakers pop Los and the some sort of defense mechanism on the power amp gets engaged.

I have tons of guesses what could be causing the problem, from faulty lamps, incorrect usage of inputs and outputs and tons more. But not sure what really is happening.
I am really afraid if this pop happens again it might destroy my speakers as it is REALLY loud. Actually I still have one of my ears ringing from it.

So I would really appreciate some help to nail down what is causing the pop and how to prevent it.

Thanks in advance! And sorry for the long post.

[admin]

Welcome to CJO, great to have you with us. The Premier 17 is a great preamp, congrats.

Not exactly sure what is happening but there are a couple of things that should be looked at.

1) The order that you turn equipment on and off goes from source to amp when turning on (and reverse when turning the system off). Do not turn components in the middle on and off.

2) You mention changing voltages? I'm not familiar with the 17LS having a voltage switch (I could be wrong)? If you are using it in Europe, it should be rewired for the proper voltage. But most importantly, there should be no voltage switching while components are on, absolutely never. Also, how do you have some 220v and 110v components in the system? It would be one or the other.

3) Last I would try to narrow the problem down to the component. This could be an amp problem for all we know. Maybe a static discharge somewhere along the line? Is everything grounded properly?

You can open up the components and look for any signs of damage such as burn marks, capacitor bulging, etc...

Let us know how it goes.

[roberto]

Hola Sakujou,

All Conrad Johnson products have a double primary wound at the power transformer, in other words, they do work at 120 ACV and 240ACV.

To change the voltage, it is not a difficult task and usually at the printed circuit board you can see what you have to do.

The Premier 17LS has two power transformers (one for the tube circuitry, one for the control circuits), each of which is protected by a fuse. A failure of either of these fuses is a symptom of a more serious problem, and a competent service technician should be consulted. In no event should these fuses be replaced with a value or type different than that originally supplied. The fuses are located on the input/output pc board at the back of the chassis. The fuses are identified as F1 and F2 on this printed circuit board.

If configured for 100 or 120V:
F1 1/2 amp, fast blow
F2 3/4 amp, slow blow
If configured for 220 or 240V:
F1 1/4 amp, fast blow

Happy listening!

[AnotherJohnson]

As odd as it may seem, it could be one bad tube. So you might try tube replacement.

The other thing, and I’ve been through this myself, is that if you’re using multiple outlets, try putting everything on one outlet. I got this tip directly from Conrad Johnson. And it worked for me.

Before this, I wanted to put everything on its own circuit, as I had done with my a Krells. I reluctantly followed this advice, and all my pops and hums and others issues disappeared.

[sakujou]

Thanks to everyone for the warm welcoming!
Also thank you for the detailed info and help provided.

So to answer one by one:

- All my equipment is 220v, since I live in Europe; Only the CJ Premier is 110v, that is why I am using a separate voltage transformer; but from the info provided by Roberto, I guess a technician could internally correct the voltage and therefor I could potentially get rid of the transformer?

- I usually do turn my equipment in the correct order; So yeah, one of the nasty pops/cracks happened when I didn't follow the order and had the power amp already running and attempted to turn on the preamp; I will definitely get it checked by a technician, but still - is it normal to get this super nasty and super loud pop/crack, just because I turned the equipment in the wrong order?

- I can buy different tubes (wouldn't mind recommendations btw, but I guess this would better be done via a separate thread), what worries me is experimenting atm, cause I can blow my speakers;

- my preamp and power amp are connected in the same power extension cord / socket / outlet; the CD transport and the DAC are in a separate outlet (but it still is part of the same electrical chain, the in wall wiring is the same, same fuse, same everything); Could it really make a difference? I can try it.

- So overall I will get a technician to check on the CJ Premier, hopefully he can find what is wrong;

- In the meantime I will not be using the theater EPL2/Unity Gain mode, since this is what cause the second loud pop;

- Now I got 2 other kinds of pop - amps were running, I was listening to music and again suddenly I get a pop, no as loud or nasty as the ones before, so a different kind, but still didn't sound nice and that is when my power amp starts blinking and becomes not operational; I am not sure if actually the power amp doesn't engage the protection / blinking mode first, because even with my previous solid state Linn pre-amp it was randomly engaging this protective mode every now and then; so the power amp needs to be checked as well, but still - with the previous preamp I didn't get any pop when this happens, while the CJ Premier pops dramatically; any idea why?

Again - tons of tanks to everyone offering help. I really appreciate.

On the positive side when the CJ works it just sings! I am literally blown away by how good it sounds with my old Paradigm Monitor 11v7s and my Lyngdorf SDA 2175 power amp. I mean I was already aware that the preamp is a very important part of the system, even my previous Linn Kolektor preamp made a huge improvement over my AVR as preamp + Lyngdorf power amp combo, but I honestly wasn't expecting to get this much from my speakers just by changing the preamp, be it for such a great machine as the Premier 17LS.
So yeah, really happy to join the CJ family. I just hope I can get it fixed before I blow my speakers.

[admin]

Thanks to everyone for the warm welcoming!
Also thank you for the detailed info and help provided.

So to answer one by one:

Always happy to help!

- All my equipment is 220v, since I live in Europe; Only the CJ Premier is 110v, that is why I am using a separate voltage transformer; but from the info provided by Roberto, I guess a technician could internally correct the voltage and therefor I could potentially get rid of the transformer?

I would change the Premier to 110v. I think have a transformer on one component introduces too many variables into the trouble shooting.

- I usually do turn my equipment in the correct order; So yeah, one of the nasty pops/cracks happened when I didn't follow the order and had the power amp already running and attempted to turn on the preamp; I will definitely get it checked by a technician, but still - is it normal to get this super nasty and super loud pop/crack, just because I turned the equipment in the wrong order?

Turning the equipment on/off in the wrong order could potenitally cause an intermittent voltage across the connectors. Ideally, it shouldn't but the possibility is there and simply turning things on/off properly would eliminate any potential associated issues.

- I can buy different tubes (wouldn't mind recommendations btw, but I guess this would better be done via a separate thread), what worries me is experimenting atm, cause I can blow my speakers;

You can try new tubes. It would also give you the oppertunity to r/o a tube problem although I don't think that is what is going on. You may want to just double check that all tubes are seated well.

I can't give you specific recommendations but I have ordered tubes from CJ directly and tube depot and have had good recommendations from both.

- my preamp and power amp are connected in the same power extension cord / socket / outlet; the CD transport and the DAC are in a separate outlet (but it still is part of the same electrical chain, the in wall wiring is the same, same fuse, same everything); Could it really make a difference? I can try it.

If you can. Put all the gear on the same outlet. I don't know if this is causing the problems you are having but ideally all the gear should be on the same line, same voltage, same outlet, etc. If you need a lot of outlets you can always use a high quality power strip or even power conditioner.

- So overall I will get a technician to check on the CJ Premier, hopefully he can find what is wrong;

- In the meantime I will not be using the theater EPL2/Unity Gain mode, since this is what cause the second loud pop;

Sounds like a good plan.

- Now I got 2 other kinds of pop - amps were running, I was listening to music and again suddenly I get a pop, no as loud or nasty as the ones before, so a different kind, but still didn't sound nice and that is when my power amp starts blinking and becomes not operational; I am not sure if actually the power amp doesn't engage the protection / blinking mode first, because even with my previous solid state Linn pre-amp it was randomly engaging this protective mode every now and then; so the power amp needs to be checked as well, but still - with the previous preamp I didn't get any pop when this happens, while the CJ Premier pops dramatically; any idea why?

Hmmm. Lots of stuff going on here. I think you really need to tackle these issues one component at a time. If you can swap out each component into a different system (even if it's just some $200 cheap sony) and try to reproduce these "pops" then it would potentially tell you where the trouble is.

[roberto]

Hola Sakujoe,

Admin had pointed out all the recommendations that you should follow. The change from 110V to 220V it is not a difficult task, but you must follow the printed circuit points to unsolder (110V) and solder (220V). Also you must change the protection fuses.

Pops and noises generally come from from tubes. Try to find from what channel the pop happens, and swap the first tube of the left channel for the right channel. (V1 swap for V2). If the pop remains in the same channel, then now you do know which is the bad tube. If you want to confirm that you have the bad tube, just swap V3 for V3.

The power sequence for your system always is:
Turning on, the last unit to turn it on is the power amp. Here does not matters the sequence, only the last to turn on is your power amp.

Turning off: Wait at least 30 seconds to one minute the power amplifier ( this is the time needed for complete or full discharge the power supply capacitors ). Then now you can proceed to turn off all the rest of your system.

Happy listening!

[bpasok]

did you ever get your problem resolved? If so, what did you find the problem to be?

[sakujou]

Hello again,

Never got the problem solved actually. Changed tubes, changed voltage transformer.
Crazy loud pops still happen. Sometimes 30min after listening to music, sometimes the Premier can work for weeks without problems.

The weird thing is the controller of the amp goes crazy - power light turns off, simultaneously different input lights turn on, almost every time in a different configuration. Wild listening at some point I hear the manual click like when tuning volume or switching inputs, then the super loud crack from the speakers happens and they start cracking repeatedly. I will upload pictures of the amp while it's in crazy mode with weird configuration of lights.

But yeah, no fix. Technician didn't find anything wrong. Most of the time the CJ sits and collects dust while I listen to my other preamp. Haven't had time to do anything with it and honestly I have no clue how to fix it.

Wrote to CJ support months ago and received no reply.

[admin]

Sorry to hear that the issue was never solved. Any chance you are in a winter/dry climate currently? This may be a static accumulation/discharge. Put a humidifier in the room and run it for a few hours before and during listening. See if it goes away or becomes less frequent.

[Big Dog RJ]

G'day mate, greetings from down unda.

I used to have this exact same problem with my ACT2 preamp. It took a while to diagnose the problem but we couldn't really narrow it down to just one issue. It was a cause of related events:

1. The mains transformers were slowly deteriorating in the Quad ESL's I was using at the time. Therefore, these bad trannys were sending off unwanted voltages back into the chain through the preamp, causing it to prematurely paralyse itself on the front panel. In order to reactivate the preamp, I would have to either depress the mute button or press + on the level setting. This would click back on with a massive pop! And the ACT2 tubes would light up again.

2. There was unwanted static build up from the Quads panels to where it was re-laying back into the preamp causing it to shut down once again paralyse itself suddenly without any warning. Sometimes this phenomenon didn't happen for a full week and all was well, until that static pop happened again.

It was so bloody annoying, I eventually sent it to CJ for a full check up/service and sold it off straight away upstate without keeping it back home just to try for longer...

Therefore, it could also be a bad interconnect where the ground shield has slightly lifted causing the sudden pop... or a bad component in your speakers x-over causing feedback into the preamp and forcing it to shut off / paralyse. Whatever it is, it's definitely not normal!

After sending the unit to CJ, they also upgraded the internal power cord and shortened the length as it was interfering with the rest of internal components. They also added a copper plate for grounding. This sorted out the problem.

The person who eventually bought my ACT2 never had an issue with it since, he's enjoying those fine tunes!
Cheers, RJ