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JVC AX-Z1010TN - Review (part II)

as said a page before, the SM says
"Idling current detection voltage check points:
L ch - TP401 pin 5 and 4 (pin 5 is the negative side)
R ch - TP401 pin 1 and 2 (pin 1 is the negative side)"
, but no joy using these :(
 
giving another try to the bias stuff this time I got lucky> the trim pots were turned down so much from their useful range (though it seemed that no one had been inside the amp before me) that slight turns didn't change anything - going 'wilder' resolved the issue and now my 1010 signs as never before :) . anyone who experiences a 1010 underperforming from his expectations should check the bias values first! having the amp working on the proper bias now has smoothed perfectly out the relentless-ish treble region, firmed the bass, and tightened PRaT - and made an extra radiator in the room ;) (when in active use - i.e. listening to music -, otherwise the heatsinks are just luke warm). moreover, if one converts the amp from 220V to 240V (the SM's pretty useful, and the procedure extremely straightforward) the bias should be re-adjusted, mind you. hope this all can help someone :rolleyes:
 
I was just about to answer your PM but now you've sorted it! Well done.

It's quite something isn't it, I don't miss NAIM at all.

It should run hot even when idling if you have the digital sources selected, Digital Pure-A.

If you PM me your email I can send you the service manual.
 
giving another try to the bias stuff this time I got lucky> the trim pots were turned down so much from their useful range (though it seemed that no one had been inside the amp before me) that slight turns didn't change anything - going 'wilder' resolved the issue and now my 1010 signs as never before :) . anyone who experiences a 1010 underperforming from his expectations should check the bias values first! having the amp working on the proper bias now has smoothed perfectly out the relentless-ish treble region, firmed the bass, and tightened PRaT - and made an extra radiator in the room ;) (when in active use - i.e. listening to music -, otherwise the heatsinks are just luke warm). moreover, if one converts the amp from 220V to 240V (the SM's pretty useful, and the procedure extremely straightforward) the bias should be re-adjusted, mind you. hope this all can help someone :rolleyes:

Thanks for posting your results - my 1010 was NOS so I am unsure is I want to open her up at this stage, but I may later on in the year.
 
Be careful! A slip and output transistors gone, or sometimes those trimpots go open, I don't know the quality but replacing them it's not a bad idea..
 
Be careful! A slip and output transistors gone, or sometimes those trimpots go open, I don't know the quality but replacing them it's not a bad idea..

Thanks for the warning, only if the values are far off the 10mA an I going to mess with them!
 
Thanks for the warning, only if the values are far off the 10mA an I going to mess with them!

... for determining of which you'd need to measure the values still, and this is exactly where that slip could be lethal (though not with the 1010 - it was built with PROTECTION that will stand even a nuclear war)> the pins on the 'check pad' are spaced VERY tightly. what I did, though, was that I pulled very small diameter (less than 1mm) silicone tubings of 0.5cm on the center pin, and after fixing a probe on the outer (1 and 5, respectively) pins, as well - hence even a serious slip of hand with the other probe (which didn't happen, BTW :D) won't make a short for sure
 
... for determining of which you'd need to measure the values still, and this is exactly where that slip could be lethal (though not with the 1010 - it was built with PROTECTION that will stand even a nuclear war)> the pins on the 'check pad' are spaced VERY tightly. what I did, though, was that I pulled very small diameter (less than 1mm) silicone tubings of 0.5cm on the center pin, and after fixing a probe on the outer (1 and 5, respectively) pins, as well - hence even a serious slip of hand with the other probe (which didn't happen, BTW :D) won't make a short for sure

Great advice, thank you!
 
I agree it is well protected! It needs to be as it's designed for loads as low as 2ohm, which is why it sings with difficult speakers like Linn SARAS and Shahanians.

I had a mate bring over a phono stage that had a DC offset when cycling the power, the 1010 instantly went into protection mode.

The phono stage continues to impress........
 
The protection is not always reliable, if the trimpot fails, bad things can happen..
Is it written in the manual what speakers support? I had a Jvc ax1100, but nowhere in the manual was mentioned support for 2 or 4 ohm speakers.
 
I bought one NOS too, so are people saying this could be adjusted to sound even better than it does at the moment? Mine's driving Obelisks and doesn't get that hot, but then I'm listening line level and not through the K2
 
I bought one NOS too, so are people saying this could be adjusted to sound even better than it does at the moment? Mine's driving Obelisks and doesn't get that hot, but then I'm listening line level and not through the K2

Mine was NOS and has been running around a year - bit the bullet, opened her up and checked the bias, one channel was around 2mV and the other around 5mV. Adjusted the pots to 10mV or thereabouts and it did improve the already excellent amp, the upper end seems slightly cleaner and strangely the bass subjectively seems to go lower.

As a matter of caution, the trimpots were sticky, making small adjustments difficult. I wish JVC had but multi turn pots in there, its easy to throw the bias voltage up to 30-40mV accidentally.

The amp does run somewhat warmer as a result.
 
By hesitating I missed out on a complete JVC titanium matching system comprising CD player: XL-Z1011 > amp: AX-R437 > matching cassette player > matching tuner all for £250.

Immaculate condition and working - did I miss an opportunity here?
 
By hesitating I missed out on a complete JVC titanium matching system comprising CD player: XL-Z1011 > amp: AX-R437 > matching cassette player > matching tuner all for £250.

Immaculate condition and working - did I miss an opportunity here?

Yes and no, the CD player is very good, the amp I'm guessing is the lower end of the titanium line, if it was the 1010 cassette and tuner, you missed a bargain :eek:
 
Hello all,

Been meaning to join for a while. Just to say it was I that bought the 1010 system mentioned above, collected it this morning. I'm a fan of this range and had a 1010 tuner previously, regretting its sale. Indeed this system does have both the 1010 tuner and cassette deck. The cassette in particular has incredible build quality and is the heaviest of the four components. I'm listening to the CD player right now through my yamaha AX-2000 and Polk LSI7s. Phenomenal quality especially the bass register. Being fair to the 437 amp I get the feeling it'll punch above its weight. 580w draw from the mains and heavier than you'd expect. Nice to see mm/mc switching too, and remote. I'll possibly be breaking this system up at some point.

Thanks
Mat
 
Hello all,

Been meaning to join for a while. Just to say it was I that bought the 1010 system mentioned above, collected it this morning. I'm a fan of this range and had a 1010 tuner previously, regretting its sale. Indeed this system does have both the 1010 tuner and cassette deck. The cassette in particular has incredible build quality and is the heaviest of the four components. I'm listening to the CD player right now through my yamaha AX-2000 and Polk LSI7s. Phenomenal quality especially the bass register. Being fair to the 437 amp I get the feeling it'll punch above its weight. 580w draw from the mains and heavier than you'd expect. Nice to see mm/mc switching too, and remote. I'll possibly be breaking this system up at some point.

Thanks
Mat

My hesitation - your gain - my loss :(.

Any chance you could take some nice clear photos of all this equipment - the listing had some good photos - but not clear on the cassette and tuner - just so that I can pine some more :)
 
Indeed I will. Even my better half thinks the CD player in particular is very good looking. Well worth the 160 mile round trip, he even gave me the rack, not to mention he accepted my £200 offer. It was all set up when I arrived, hardly used the last ten years apparently. I'll take some proper photos and post them later tonight.

Cheers
Mat
 


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