Phono stage fault

[Stiffy]

I have an old Trio KA 3055 amp with a dodgy phono stage, basically it doesn't work on the right channel.
Any ideas what might have went wrong? Will it be repairable and is it worth it?

It's just my spare amp and doesn't owe me much so I might be better off looking for a cheap seperate pre amp.

[awkwardbydesign]

First thing is to swap the leads around to make sure it is the amp and not the leads or TT. Then wiggle them gently to check the sockets, then open the amp and check the soldering of the sockets isn't faulty. Unplug it before opening of course! And could the selector switch be the problem?
Often these faults are mechanical rather than electronic in nature.

[Stiffy]

First thing is to swap the leads around to make sure it is the amp and not the leads or TT. Then wiggle them gently to check the sockets, then open the amp and check the soldering of the sockets isn't faulty. Unplug it before opening of course! And could the selector switch be the problem?
Often these faults are mechanical rather than electronic in nature.

The turntable and leads are fine, they are currently connected to my main amp and work perfectly.
I will check the solder at the connections. The strange thing about this is that a few days after trying the amp out and realising the phono stage was faulty the inbuilt RCD in my house fusebox failed. The sparky who replaced it said he'd never known one fail and it's a fairly new house. It may have just been a coincidence but I've never tried the phono stage since because I cant afford that to happen again. The rest of the amp works fine.

[awkwardbydesign]

I think it must be a coincidence. I don't see how that would make it fail, it would just trip! And surely it would blow fuses before that anyway.

[struth]

i would be surprised if it had any connection if the amp is working other than the phono stage in it. as richard says it is quite possibly a dry joint. failing that look out for any components that look odd. swollen leaki!g capacitors and burnt resistors etc.

[Stiffy]

Thanks to you both....I'll have her apart at the weekend and try to see whats what.

[awkwardbydesign]

Thanks to you both....I'll have her apart at the weekend and try to see whats what.

And post pics.

[The Barbarian]

I have a total of four Trio amps. 1x'KA2000', 2x'KA2000a' & 1x'TK150T' all originally lost one channel. all recapped & ok.

[Floyddroid]

Nip over to your nearest Richersounds and buy yourself a little Cambridge Azure phono stage.:)

[Stiffy]

I have a total of four Trio amps. 1x'KA2000', 2x'KA2000a' & 1x'TK150T' all originally lost one channel. all recapped & ok.

Does anyone know what the likely cost of recapping would be?

[Desmo]

Do you own a soldering iron? Its not too difficult a job to DIY.

[awkwardbydesign]

Do you own a soldering iron? Its not too difficult a job to DIY.
:eek:

[Stiffy]

Do you own a soldering iron? Its not too difficult a job to DIY.

No, I could get one but I wouldn't have a clue how or where to start.

[Stiffy]

Here's the pics guys…..may I have your comments please as I haven't got a clue what I'm supposed to be looking at??
Soz about the nanas in the background.

[walpurgis]

I suspect Andr'e may be your man on this.

[Stiffy]

A few more pics……

[The Barbarian]

Na don't do Trio amps past 'KA2000a' {'2002'/'4002' at a push}

[The Barbarian]

Had trio amps all over the place before christmas. Put things away since then :eyebrows:

[struth]

Ooh, a trio of trios. very nice.....you must have a huge storage facility Andre. I aint even got 1 cupboard:(

[The Barbarian]

Yeh i got a store room but i got shut of a lot of gear mainly jap stuff. Kept all the Trio amps tho. Other than them i just keep the British vintage classics Quad/Ferrograph/Armstrong/Rogers/Leak etc..

[Stiffy]

I've just plugged her in and tried the phono stage again.
It's the left channel thats inop and if I alter the mic level pot I can hear fairly quiet crackling through that channel.
The right channel is perfect.

[The Barbarian]

John it basically needs a good service but the be honest i would not really spend anything on it..Be cheaper getting summert else..

[Stiffy]

John it basically needs a good service but the be honest i would not really spend anything on it..Be cheaper getting summert else..

OK, thanks for the advice, It's just a spare amp so I'm not overly bothered.

[The Barbarian]

Looking at the Circuit diagram i don't see anything that could really be an issue. There is a pair of Hitachi 'HA1457' Semmiconductors {one per channel} for the easiest you could de-solder these & swap them over see if the other channel comes to life. You can still buy these btw..

[Stiffy]

Looking at the Circuit diagram i don't see anything that could really be an issue. There is a pair of Hitachi 'HA1457' Semmiconductors {one per channel} for the easiest you could de-solder these & swap them over see if the other channel comes to life. You can still buy these btw..

Ok, thanks for taking the time to look for me.

[walpurgis]

I see it's now on eBay.

[Stiffy]

I see it's now on eBay.

Yep, along with my other stuff.
What do you think of the starting price?

[walpurgis]

Yep, along with my other stuff.
What do you think of the starting price?

About £30 too high! :lol:

(you never know, somebody may need one)

[Stiffy]

About £30 too high! :lol:

(you never know, somebody may need one)


Ya nasty pasty, :eek: LOl

[The Barbarian]

:lol: