Jadis Monoblock Amplifiers

[microstrip]

That's why they came out with the Mk. II version.

In fact, for long the main reason for Jadis MKx versions was simply getting the attention from reviewers and reviews in magazines. There was little more than cosmetics such as new RCA or speaker connectors or a change for a more recent version of components between MK's. The exception is either very old models (early 80's) or some recent changes to more powerful KT150 tubes in some models.

Jadis users went in problems mainly due to two reasons - poor quality of tubes or inadequate tubes or poor support/service due to incompetent distributors who were not able to service them. Jadis circuits are extremely simple - classic designs, not rocket science. In the 90's many people had trouble due to unavailability of good power tubes - we all remember the horror stories of early chinese tubes, of extremely low reliability and quality. Russian sourced power tubes only came in the middle or late 90's, as far as I remember.

Fortunately our local distributor has a top technician and top service - any trouble with Jadis is quickly solved. I owned Jadis equipment several times, and I know many audiophiles who are happy Jadis owners - my old JA30 (from the early 90's) is still performing great a few kilometers from me--

I owned a JP80 mkII long ago - very similar to the JPS2, but with phono and it was noise free - the 1998 Stereophile measurements reported very good line signal to noise ratios.

 

[lars66]

Hi,

I don't understand. Did you send the preamp to Jean-Christophe Calmettes at the Jadis factory to have it fixed?

I did not send the preamp to the honorable gentleman for several reasons:
1. Jadis technical support just wrote in the email what it says in the user manual and it refers to various noises.
2. Tech support did not offer to find out what the problem was.
3. Technical support did not suggest that I send the preamplifier to them for inspection and possible repair if there is a defect.
4. Technical support only suggested that I contact their distributor for Serbia. Their distributor in Serbia does not have the possibility of testing, finding out what the problem is, nor the possibility of servicing the device in an authorized service center. Their distributor, instead of trying to solve the problem, wanted to sell me a very expensive network filter...The JPS2S is a new device out of the factory box. Should he have a problem?

 

[microstrip]

(...) 4. Technical support only suggested that I contact their distributor for Serbia. Their distributor in Serbia does not have the possibility of testing, finding out what the problem is, nor the possibility of servicing the device in an authorized service center. Their distributor, instead of trying to solve the problem, wanted to sell me a very expensive network filter...The JPS2S is a new device out of the factory box. Should he have a problem?

Ok, unfortunately you have mostly a personal conflict and a legal problem. Usually when a manufacturer gets a distributor in a country, the distributor gets the full responsibility of warranty and technical service. If the unit is not working properly and he can't fix it he is supposed to reimburse you. If the product needs to be returned to the factory for service under warranty he is responsible for such duty and all the associated expenses.

 

[lars66]

I cannot agree with you. I believe that the main problem is the construction of the preamplifier and/or a bad choice of lamps that have a lot of noise. I believe that the amplifier is not defective, but rather a characteristic of the JPS2S. I would be very happy if someone who has experience with this preamplifier could give their impressions. Thank you all for your comments.

 

[Ron Resnick]

Some, if not many, companies in this small, niche industry are underfunded and do not perform adequate testing of new models. Low production volume sounds fancy and bespoke, but it contributes to unreliability in the field. Small production volumes occasion high cost and imperfect reliability.

As consumers in this hobby, we understand that this is how things work. I am okay with this. There is no other way for underfunded companies to produce complex, state-of-the-art pushing components. I love this industry and it's passionate designers.

But the flip side of this, I feel very strongly, is that when there's a problem the manufacturer should fix it! A manufacturer should not let it remain "the customer's problem." I feel this is an implicit deal, an implicit understanding, between manufacturers and consumers in this very unusual industry. And if the manufacturer cannot fix it, they should give you a full refund. Any manufacturer who does not operate this way should be called out publicly for it, so other innocent consumers do not suffer the same fate.

I understand the repair inquiry process you went through. To me that's all noise and evasion by the distributor.

I would've sent the preamp directly back to the factory myself for evaluation and, if necessary, repair. If they found nothing wrong, then you pay the shipping and logistics costs. If they found something wrong, then they fix it and they should reimburse you for the shipping and logistics costs.

 

[microstrip]

I cannot agree with you. I believe that the main problem is the construction of the preamplifier and/or a bad choice of lamps that have a lot of noise. I believe that the amplifier is not defective, but rather a characteristic of the JPS2S. I would be very happy if someone who has experience with this preamplifier could give their impressions. Thank you all for your comments.

The JP2S is surely as noise-free as its tubes. But you will be in a poor situation in the future if you can't get a local solution for something as simple as a tube swap.

Some, if not many, companies in this small, niche industry are underfunded and do not perform adequate testing of new models. Low production volume sounds fancy and bespoke, but it contributes to unreliability in the field. Small production volumes occasion high cost and imperfect reliability.

IMO Jadis is not exactly a "small, niche industry and are underfunded and that do not perform adequate testing of new models. " They sell a lot around the world.

Long ago Gary Koh posted a detailed report with many photos of his visit in WBF. https://www.whatsbestforum.com/threads/a-visit-to-jadis.10696/

They have been in the business for more than forty years. I know they had great trouble with US distribution some time ago, but I think is now settled.

As consumers in this hobby, we understand that this is how things work. I am okay with that. I love this industry and it's passionate designers.

But the flip side of this, I feel very strongly, is that when there's a problem the manufacturer should fu*#ing fix it! I feel this is an implicit deal, an implicit understanding, between manufacturers and consumers in this very unusual industry. And if the manufacturer cannot fix it, they should give you a full refund. Any manufacturer who does not operate this way should be called out publicly for it, so other innocent consumers do not suffer the same fate.

I understand the repair inquiry process you went through. To me that's all noise and evasion by the distributor.

I would've sent the preamp directly back to the factory myself for evaluation and, if necessary, repair. If they found nothing wrong, then you pay the shipping and logistics costs. If they found something wrong, then they should reimburse you for the shipping and logistics costs.

Again, it is not the way we usually deal with such things in Europe. We do not have details enough to appreciate the real situation.

BTW, this what I wrote in the referred thread (the JPS2 is essenciallly a JP80 without phone section) :

"Recently I hosted a Jadis JP80MC mk2 - JA 80 system for some months. As the power amplifiers were not powerful enough for the Aida's I did not keep it for long. The combo needed some care when choosing cables , but the preamplifier was something really exceptional. It was completely noise free and the treble was airy and delicate, very detailed but natural. Listened trough the Aida's fantastic tweeter it was an experience - Paniagua Tarantula Tarantella never sounded the same after it left. Extrapolating from the sound of the tweeters of the Genesis 8300 - my only experience in my room with Genesis - I can imagine that Jadis will be a good match with Genesis speakers."

Disclaimer - I could happily live with a JP80MC , the JA200's and the Aida's ...

 

[Atmasphere]

I believe that the main problem is the construction of the preamplifier and/or a bad choice of lamps that have a lot of noise.

FWIW the preamp uses 12AX7s and a 12AU7 according to the manual. You should be able to find low noise examples of those tubes.

Is the noise in both channels or just one?
If in both, is it at the same level in both channels?
Is the noise a hiss, buzz or hum?

Answering these questions may help to sorting things out.

 

[Ron Resnick]

I love Jadis. I have JA100s. I may move up to JA120s.

I came extremely close to buying a JPS2 as my last preamp. It's a wonderful preamp, and it normally should not have any noise problem. (As a point of reference I never expect tube electronics to be as quiet as the quietest solid-state electronics. I think that to expect this is unrealistic.)

 

[lars66]

FWIW the preamp uses 12AX7s and a 12AU7 according to the manual. You should be able to find low noise examples of those tubes.

Is the noise in both channels or just one?
If in both, is it at the same level in both channels?
Is the noise a hiss, buzz or hum?

Answering these questions may help to sorting things out.

Noise is heard on both channels, same level on both channels. The noise is of the same loudness level and does not depend on the position of the potentiometer. Noise is heard even when the volume level is set to zero. The noise, as I already explained, is like the noise of tubes, only very very loud.

 

[Ron Resnick]

Hi Lars,

If you have replaced the tubes, and you have eliminated grounding or hum as a possible source of the noise, and the noise is still there, just send the unit to the factory. I don't understand why you have made such a project out of this noise problem.

 

[DasguteOhr]

Cd input(12au7)and other inputs (3x 12ax7)the same noise?

 

[microstrip]

Noise is heard on both channels, same level on both channels. The noise is of the same loudness level and does not depend on the position of the potentiometer. Noise is heard even when the volume level is set to zero. The noise, as I already explained, is like the noise of tubes, only very very loud.

First I would replace the power supply regulation tubes. Next the signal tubes. Some of the signal tubes are shared between channels.

 

[Atmasphere]

Noise is heard on both channels, same level on both channels. The noise is of the same loudness level and does not depend on the position of the potentiometer. Noise is heard even when the volume level is set to zero. The noise, as I already explained, is like the noise of tubes, only very very loud.

This suggests the Voltage regulator is oscillating. If there are tubes in the power supply, replace them and see if that calms it down.

 

[lars66]

Hi Lars,

If you have replaced the tubes, and you have eliminated grounding or hum as a possible source of the noise, and the noise is still there, just send the unit to the factory. I don't understand why you have made such a project out of this noise problem.

I didn't cause the problem. The problem is with the brand new preamp. It is a high-end, high-priced component. Such things should not happen. You're telling me not to make a fuss about it? Sorry but I have to, everything I have stated is a great shame for Jadis. You are telling me to send the preamp to the factory. Dear sir, it's not a letter, it's two devices with a total weight of 31 kg. What bothered me the most was that Jadis technical support did not want to look at the problem in its entirety and try to help at least with advice. If you think it's okay for a brand new component to have these kinds of problems then we're wrong. Thank you anyway for responding to my post.

 

[Atmasphere]

I didn't cause the problem. The problem is with the brand new preamp. It is a high-end, high-priced component. Such things should not happen. You're telling me not to make a fuss about it? Sorry but I have to, everything I have stated is a great shame for Jadis. You are telling me to send the preamp to the factory. Dear sir, it's not a letter, it's two devices with a total weight of 31 kg. What bothered me the most was that Jadis technical support did not want to look at the problem in its entirety and try to help at least with advice. If you think it's okay for a brand new component to have these kinds of problems then we're wrong. Thank you anyway for responding to my post.

Wasn't the preamp under warranty?

Nothing is perfect, especially people, and people make things other people buy. So things can go wrong on that account. That is what warranties are for.

I realize it has some weight, but they are responsible for shipping back to you. They are not responsible for where you live. That is how most warranties are set up.

I don't understand not wanting to provide support. I know it happens though- I needed support for a Garmin GPS recently and couldn't get it (it was brand-new). That resulted in my having to return it to the dealer and getting its cost refunded. I don't buy Garmin products anymore, despite them being one of the leaders in the field of consumer GPS products. I stay away from Shimano (bicycle) components for the same reason.

Hopefully high end audio is the sort of endeavor where manufacturers stand behind the products they made because they took pride in making them, no matter how old they are.

 

[microstrip]

I didn't cause the problem. The problem is with the brand new preamp. It is a high-end, high-priced component. Such things should not happen. You're telling me not to make a fuss about it? Sorry but I have to, everything I have stated is a great shame for Jadis. You are telling me to send the preamp to the factory. Dear sir, it's not a letter, it's two devices with a total weight of 31 kg. What bothered me the most was that Jadis technical support did not want to look at the problem in its entirety and try to help at least with advice. If you think it's okay for a brand new component to have these kinds of problems then we're wrong. Thank you anyway for responding to my post.

Surely these things should not happen. But the Jadis is a simple preamplifier and can be easily diagnosed by anyone with minimum expertise in tube electronics. No rocket science there.

Did you try a new set of tubes in the power supply?

 

[lars66]

When ordering the JPS2S preamplifier and the JA 80MKII amplifier, I also ordered a set of all spare lamps. Yes, I tried replacing the lamps in the power supply. The problem remained. I have one observation. When the equipment is not used for a while, the noise is noticeably lower, but it still bothers you during music playback. When I use the preamp for a few days the noise gets louder and louder.

 

[Atmasphere]

When ordering the JPS2S preamplifier and the JA 80MKII amplifier, I also ordered a set of all spare lamps. Yes, I tried replacing the lamps in the power supply. The problem remained. I have one observation. When the equipment is not used for a while, the noise is noticeably lower, but it still bothers you during music playback. When I use the preamp for a few days the noise gets louder and louder.

When did you receive the preamp?

 

[lars66]

June 24, 2023. I know it's been a long time. In the meantime, I checked everything that could have affected the noise. The JPS2S is extremely sensitive to the proximity of its power supply. When they are close to each other, a very loud hum is heard, as if something is broken. The hum disappeared when I removed the power supply from the preamp. The noise still remains...

 

[microstrip]

June 24, 2023. I know it's been a long time. In the meantime, I checked everything that could have affected the noise. The JPS2S is extremely sensitive to the proximity of its power supply. When they are close to each other, a very loud hum is heard, as if something is broken. The hum disappeared when I removed the power supply from the preamp. The noise still remains...

It is terrible, but unless some one services it the problem will not be solved. Assuming you dealer will not solve it, all you can do is sending it to Jadis.
It seems it is a power supply issue, but many things can cause such problem - even a simple poor solder join ...

An oscilloscope is needed for such diagnostics.