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EAR 834 problem

A

Andrewxyz

pfm Member
I was listening to radio earlier when I heard a loud buzz follow by silence. Music gradually returned on both channels but on checking the amp it appears that one of the EL34's on the left hand side has died.

Is this a back to Huntingdon job or can I replace it myself ?

I seem to recall reading that changing valves on this model is a pain as the were glued in for transit.

Edit. This is the EAR 834 Integrated amp, not the phono stage.
 
Hi

Probably worth giving them a call - 01480 210004.

The amp is self-biasing so you should just be able to put in a new EL34 if there is no other damage.
 
Found the manual. "To remove the valve cage you have to take the base of the unit & undo a couple of captive pozidrives. The tubes can then be pulled from the top & pushed from below through the holes in the circuit board, using a pencil or similar. Tubes are glued in place to prevent them coming loose in transit so some force may be required."

Sounds like a recipe for a damaged circuit board or a hand full of glass fragments!

I bought it 2nd hand in 2012 so it may be time for a service.
 
Ah it was only as I live in Yorkshire but work a couple of hundred yards from the EAR Yoshino Unit in St Neots. It was a long shot as i could have dropped it in for you. I dont need much of an excuse to go in there.
 
Is it worth trying to soften the glue which something like nail polish remover with acetone in it first. A s.few drops on the underside of the valve base may help ease the pressure on pulling the valve out...
 
Has Mr De Paravicini used Edicron EL34s? I think he usually does.

If so, I may be able to help with a replacement and am in Merseyside.

Mull
 
hifi-dog said:
Is it worth trying to soften the glue which something like nail polish remover with acetone in it first. A s.few drops on the underside of the valve base may help ease the pressure on pulling the valve out...
Click to expand...

I'd be a bit wary about that. Acetone dissolves lots of things including many plastics and acrylic.

Just sayin..
 
Andrewxyz said:
Found the manual. "To remove the valve cage you have to take the base of the unit & undo a couple of captive pozidrives. The tubes can then be pulled from the top & pushed from below through the holes in the circuit board, using a pencil or similar. Tubes are glued in place to prevent them coming loose in transit so some force may be required."

Sounds like a recipe for a damaged circuit board or a hand full of glass fragments!

I bought it 2nd hand in 2012 so it may be time for a service.
Click to expand...

Tim is many things but not stupid.

I suspect that he may use a 'non hardening glue'. Pushing on the centre (plastic) lug of the valve bass from below should not do any damage as I'd be surprised if he didn't use ceramic valve bases in metal frames riveted into a metal frame.
You could also rock the valve very slightly from above, but DO NOT twist it, as this will break the locating key off the valve lug. (not a big deal if the valve is dead) or damage the valve base. ( much more of a big deal....)

Mull
 
A tiny drop applied the tha valve base underside with a cotton bud was all I was thinking..nor sloshing it all over .....but never mind
 
Cheers everyone, I'm in Madrid at the moment so will have a go at removing the valve when I'm home next week. I think the valves are just labelled EAR.
 
After getting back from Spain I've been lurgified, so haven't looked at this until today.

The bottom came off easily, the valve cage as well. The valve came out if the socket with a gentle pull, no evidence of adhesive used, so they may have stopped doing this.

A few pics below.

32938017592_746199a126_z.jpg
[/url]IMG_3192 by Andrew Clark, on Flickr[/IMG]

32248406014_035098447c_z.jpg
[/url]IMG_3195 by Andrew Clark, on Flickr[/IMG]

32248407034_cbdc60b0ed_z.jpg
[/url]IMG_3196 by Andrew Clark, on Flickr[/IMG]
IMG_3199 by Andrew Clark, on Flickr

I may as well take the other cage off & do some dusting....

32278893433_52933722df_z.jpg
[/url]IMG_3198 by Andrew Clark, on Flickr[/IMG]

Now I need to source a replacement valve, and probably a spare in case another goes in the future.

Would EAR sell these at a reasonable price or would any decent make be suitable ?
 
In general you can buy the valves much cheaper elsewhere e.g. Watford Valves. EAR do test them though, so it's whether you think that's worth the additional money...
 
I'd think about replacing all the EL34s in one go. They are probably all getting towards the end of their life now.

I'd second the recommendation for Watford valves.
 
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