Official Jolida JD9 thread

I use the first gain switch for my mc and mm carts. I just move the outputs from low to high and vice versa and change resistance settings from 47k to 100 ohms (4th and 1st switches). The low outs go through a variable resistor, which despite claims to the contrary, do not seem to degrade sound quality to my ears.
 
I use the first gain switch for my mc and mm carts. I just move the outputs from low to high and vice versa and change resistance settings from 47k to 100 ohms (4th and 1st switches). The low outs go through a variable resistor, which despite claims to the contrary, do not seem to degrade sound quality to my ears.

This makes sense and aligns with my findings as well.

With Gain SW 1 up the gain on the high output is ~60db which is suitable for many MC's, the gain on the low output is ~40dB which is suitable for most MMs.
 
Hello all! I'm new to this forum and thread, and just took delivery of a new Jolida JD-9II Upgraded. I got it hooked up and started to listen to some of my favorite vinyl. I was just starting to enjoy the sound when, during the third track, all of a sudden the preamp starts what I would call "motorboating" really loud, both channels!! The woofers on my Thiel CS6's were popping in and out pretty well. I turned down the volume and changed the input on my line preamp, then back again, and it had stopped. Then it occurred another couple of times the same way. I tried switching out cables and even line preamps, but it still does the same thing - randomly and loudly. It does seem when you stop loading the output, it stops.
I am using the high output jacks, and have the dips set on low MM gain, and 47K load - no cap load.

I've reading with interest the posts in this thread, but wasn't able to fine that anyone else had this problem.

Does anyone have an idea what's going on? I'll probably return it for another, but I'd like to know what might be going on with it.

Thanks
TK
 
Hello all! I'm new to this forum and thread, and just took delivery of a new Jolida JD-9II Upgraded. I got it hooked up and started to listen to some of my favorite vinyl. I was just starting to enjoy the sound when, during the third track, all of a sudden the preamp starts what I would call "motorboating" really loud, both channels!! The woofers on my Thiel CS6's were popping in and out pretty well. I turned down the volume and changed the input on my line preamp, then back again, and it had stopped. Then it occurred another couple of times the same way. I tried switching out cables and even line preamps, but it still does the same thing - randomly and loudly. It does seem when you stop loading the output, it stops.
I am using the high output jacks, and have the dips set on low MM gain, and 47K load - no cap load.

I've reading with interest the posts in this thread, but wasn't able to fine that anyone else had this problem.

Does anyone have an idea what's going on? I'll probably return it for another, but I'd like to know what might be going on with it.

Thanks
TK

You might have a defect and have to return it. You never state the cartridge or preamp?

Assuming it's moving magnet you should use the low output, with gain switch #1 up.

The cartridge might like to see some capacitance, especially Shure and Ortofon.

Keep the power cord away from signal cables too.
 
The cartridge is a Sumiko Blue Point special EVO III, high output MC (2.5mv). I went with high output gain switch #1 up thinking that was the best for low noise. That shouldn't have an effect on this oscillation issue, should it? Sumiko says keep capacitance below 100pf including cables. I tried 100pf and 47, and liked none the best, from a sound standpoint. All cables were dressed. The preamps I used were Aragon Soundstage in analog direct mode, and an Apt Holman preamp, recapped and new opamps, both in excellent working order. Issue occurred with both preamps.
The unit is probably going back, but I might talk to Jolida first. I was wondering if anyone here had experienced the same thing.
 
The cartridge is a Sumiko Blue Point special EVO III, high output MC (2.5mv). I went with high output gain switch #1 up thinking that was the best for low noise. That shouldn't have an effect on this oscillation issue, should it? Sumiko says keep capacitance below 100pf including cables. I tried 100pf and 47, and liked none the best, from a sound standpoint. All cables were dressed. The preamps I used were Aragon Soundstage in analog direct mode, and an Apt Holman preamp, recapped and new opamps, both in excellent working order. Issue occurred with both preamps.
The unit is probably going back, but I might talk to Jolida first. I was wering if anyone here had experienced the same thing.

Never heard of this problem before. Did you swap tubes?

I still believe you only need about 40dB of gain. Low output, all switches down, or sw 1 up. High output is for LOMC.
 
I did not swap tubes - just checked to see if they were plugged all the way in. The oscillation occurs seemly equally in both channels, so I didn't suspect a bad tube - maybe power supply? Switch #1 up with low output was way too low volume. Which in general is better, low gain and high output, or vice versa? I thought the low output was just the high output run through a resistor divider, since there's only one set of output caps. Also thought the higher the gain, the greater potential for noise, hence my choice.
 
If the only ill effect from the low outs was low volume, I'd guess you're overloading your preamp with the high outputs.
Can you get sufficient volume from the low outs if you just crank the volume past what you normally do?
 
I'm talking very low volume, to the point where I could not get sufficient listening volume. Are you saying I'm overloading the inputs of the line stage, or overloading the Jolida? Either way, how would either of those conditions cause motorboating? BTW, I've just got off the phone with Jolida, and they are saying there's definitely a problem with the preamp, probably power supply or a bad connection. I'm waiting for a call back from their tech. I also get a lot of noise if I turn the Jolida off while the LS is still on, and they said that's also not right.
 
I was thinking of the line stage. I've seen different pre's handle overload in unusual ways. But I'd have to agree, sounds like an issue with the JD9.
 
I talked earlier with Jerrod at Jolida. He agrees the unit has a problem, and a new one will be on the way from them. One point he brought up was possible cartridge interaction, but I'm not sure how a cartridge problem/interaction could cause motorboating oscillations in the phono preamp Any thoughts on that?
 
Never heard of a cartridge motor-boating, but every 2.5mv rated cart I've used in my JD9 had adequate gain from gain 1 switch and low outs.
 
Never heard of a cartridge motor-boating, but every 2.5mv rated cart I've used in my JD9 had adequate gain from gain 1 switch and low outs.
Interesting. When I talked to Jolida, Jerrod's recommendation for a 2.5mv cartridge was gain 2 switch and low outs. He verified that low outs are just high outs through a resistor divider. I wonder if that would increase noise.......
 
Interesting. When I talked to Jolida, Jerrod's recommendation for a 2.5mv cartridge was gain 2 switch and low outs. He verified that low outs are just high outs through a resistor divider. I wonder if that would increase noise.......

You definitely need use low output. If switch 1 up doesn't do it then try switch 2.

I have the schematics and posted earlier about the voltage divider. There is a 20dB d difference better the two outputs. High output is the high gain output for moving coil.

If you still have problems I would return it.
 
You definitely need use low output. If switch 1 up doesn't do it then try switch 2.

I have the schematics and posted earlier about the voltage divider. There is a 20dB d difference better the two outputs. High output is the high gain output for moving coil.

If you still have problems I would return it.
I did try the low output jacks, but not the switch 2. Is there a chance that using the high outputs with switch 1 somehow caused the motorboating I don't see how but I could be wrong. In any event, Jolida seemed to think that the unit had a problem and it's already on the way back. A new one from them is in build and will be coming to me shortly. BTW, where can schematics be obtained?
 
I have an issue with the JD9. I am getting a radio signal through the speakers when the JD9 is powered on.

I guess this particular problem has been covered in other forums and on contacting the store from whom I purchased the unit, they said it is normal if there is a radio tower nearby which I do not think so.

Has anyone experienced this and what can be a solution? Will changing the stock RCA cable from my Technics SL1200 TT stop the reception?
 
Try adding or increasing the capacitance.
If no help, try shielded cables.

I live a couple of miles from a high power station (107) and maybe a half mile from a college station (88) and never heard a squeak from either side of the FM band.

The only time I've ever heard FM bleed into my phono was when I left my tuner on while playing vinyl. That was the fault of my line stage.
 
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