Nothing In Particular

[Nick]

Cool. I had a look at the service manual mainly to see what sort of control system it was. Very simple, but interesting (well I thought so) was the motor was clearly related to the sp10 one, using a high frequency signal to a set of coils that were then used to generate the three phase signal in the correct timing.

[Ant]

It is a fair bit different looking to the sl1100 /110 motor and the sl1200mk1 and 120mk1, a first attempt at cost saving when they realised they were onto something with their first gen motors maybe?

The all in one mkl15 motor seems to have been a parallel development as a standalone unit for sale to other companies, i can only think of the sl2000 that technics did that used it. Derivatives of that are all over in other companies products

[Daniel Quinn]

Cressy why did the amp go tits up , have you investigated ?


Paul , best wishes . Glad to see your positive mood .

[Mike H]

Yes I'm also curious!

[ed]

Cressy why did the amp go tits up , have you investigated ?


Paul , best wishes . Glad to see your positive mood .

I'm guessing(like I always do) but doesn't it sound like pp failure, i.e 1 transistor gave out ?

all the very best Paul.

[Daniel Quinn]

For three year I’ve been plagued by neurological pain . The only respite I get it’s when I’m asleep .

I’m okay if I occupy my mind but sitting down and reading or watch tv , the pain takes over . The past 6 months it as got worse.

Last month I tried cannabis capsules . I use a third of a capsule , not wishing to get high .

They seem to be working . They someone manage to minimise the impact the pain as, without masking it .

Now let’s see if I can get them prescribed

[Cressy Snr]

Cressy why did the amp go tits up , have you investigated ?

Yep, as Ed has said, one side of the right channel output pair blew, taking several small resistors on the board with it. Why it did that, I don’t know!

TBH, I can’t be arsed anymore with this stuff, apart from making tube headphone amps, which to me are a revelation in high quality sound, providing one can get them quiet that is. Must build an OTL HPA sometime, with my 6H30s, or Andrew I’s kindly donated 6N6Ps or ECC99s, or even 6080/6AS7s as the output tubes. It’ll certainly have to go some to beat the 1626s but it would be silly not to find out.

Apart from anything else, I never expected the little Denon CD tuner-amp to sound anything like as brilliant as it does. Because the Denon was an impulse buy when I was totally pissed off, I was apprehensive after I’d pulled the trigger, wondering if I’d done the right thing, not expecting a great deal out of it, and ready to nit pick and find fault. However, I can’t find anything to whine about. It just goes about its business and once set up, is completely fuss free and works a treat with my new Q Acoustics 3010i bookshelf speakers. From a sound quality and ease of operation perspective, the missus loves it too, so it’s a win-win situation.

It’s never off.

[Mike H]

Cressy why did the amp go tits up , have you investigated ?


Paul , best wishes . Glad to see your positive mood .

I'm guessing(like I always do) but doesn't it sound like pp failure, i.e 1 transistor gave out ?

Which amp is this?

[Cressy Snr]

Which amp is this?

A couple of NVA boards with power supply and input selection/volume control, in an ally box. I’ve run those boards in various boxes since 2019 with no problems, until there were.

[Mike H]

Oh NVA, ta. Yes I remember.

[Ant]

The technics is now spot on, fires straight up to speed and doesnt drift. All good, the work done has sorted it completely.

The jvc however, has me a bit stumped.

It hums on both channels, not very much, but enough for me to investigate. I cant find a fault. Hum is a bit louder on the right channel.
Ive examined all the wiring, cant find a short anywhere. It'd be dead on a channel if there was a short and it isnt.
Ive changed the headshell, its the same.
Changed the cart, its the same.
Changed the headshell leads, its the same.
Whether the deck is turned on or not doesnt affect it so its not something radiating from the electronics
The wiring is shielded where it comes from the arm base and to a tag strip, this is fine.
It isnt the internal ground wire on the arm tube as both channels would be humming at the same volume.
There are a couple of bent metal shields in the plinth which are also fine. All i can think of at the moment is that there is a duff connection somewhere which is high resistance or something.

Anyone have any ideas?

[Morgan Jones]

Test without headshell plugged in - it should be clean. Since it's different on each channel, that rather suggests that it isn't a hum loop. I'd be looking at earth bonds to chassis. Don't just trust a DMM. Also, you'd be amazed how badly people do earth bonds. Serrated washers help, but they can't cut through serious corrosion, surface coatings, or anodising. I'd take all of those earth bonds apart, clean their surfaces and rejoin them. Could even be a dodgy crimp from the wire into the tag that goes onto the amplifier and takes earth to the turntable. I expect the signal cables are coaxial rather than twisted pair in screen. A balanced connection between turntable and pre-amplifier will reduce hum even if the pre-amplifier input isn't balanced.

[jack]

Just a slight heads-up... I'm selling my plasma speaker thingy... In the for sale bit...

[brig001]

Does anyone know why I have “Last day on earth” in my calendar for tomorrow? I must have read it somewhere…

Anyway, it has been nice knowing you all

Brian

[andrew Ivimey]

Maybe we should put paper bags over our heads.

Last orders please!
( snigger)