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Tube recommendations for an EAR 834p

I'd always assumed the two phono ECC83 in my Croft Integrated were left/right channels so needed to be matched. Looking at the thread above it seems people use different ECC83s in different points of the 834P. Did I assume wrong?
 
Thanks for the simple explanation Jez - even I can follow that, when that simple.

I picked up WAY back that matched valves were not needed, not least because of the effect of feedback. It does come up regularly and quite a few get the hump when told that it doesn't matter, though they seldom argue with Jez :)
 
Vinny said:
Thanks for the simple explanation Jez - even I can follow that, when that simple.

I picked up WAY back that matched valves were not needed, not least because of the effect of feedback. It does come up regularly and quite a few get the hump when told that it doesn't matter, though they seldom argue with Jez :)
Click to expand...

Eh??? "They" argue with me over even whether it's electrically possible for a fuse, or a box of soil with earth plugs on it.. to change the sound.... even though I'm an electronic engineer and "they" are often a picture framer or a cab driver or a brickie:rolleyes: :D
 
I've not noticed any statement from you about matched pre-amp' valves, feedback etc. get questioned, if it has been, I've missed it.
The rest............................... best not to bother on your part; fairy dust, super special grade components,etc. etc. etc. ad nauseam
 
Gwantommo said:
I wasn't aware you could alter any settings, I assumed it was just MM or MC. I'm new to this so learning as I go. At the moment I've got it switched to MM, as I'm using a Soundsmith MI cartridge which I believe is similar to a high output MC.

I'm going to have to pop the lid off and have a look at what's in there.
Click to expand...

No, there aren't any switches you can play with. In my case I'm using an MM cartridge and to get it optimised for the spec of my cartridge I needed to raise the loading capacitance and lower the resistance.

I made myself up a selection of loading plugs and did some listening to establish the best values before opening it up and getting the soldering iron out.

In my particular case the values were way off until I did this and I got a big improvement. However, other cartridges may already be operating more optimally than mine was.
 
So last night I started to get some noise from the 834 when no record was being played. A similar sound to the run-out grooves. Is this a tube failing? I've yet to open it up as I'm a bit scared to get the screwdriver out on any electronics and can't find a user guide anywhere. If anyone knows of one they could point me to that would be appreciated.
 
Doesn't sound like a valve going. They tend to go "ting" or "wheeeeee" or "crackle." Don't be afraid to open up an 834p. There's not much in it to see.

The valves in it are thruppence ha'penny. Get some spares and swap them out.
 
Gwantommo said:
So last night I started to get some noise from the 834 when no record was being played. A similar sound to the run-out grooves. Is this a tube failing?
Click to expand...

It is my understanding that going noisy is one of the commoner faults that develop with valves. That said, if it is both channels, that would be extremely unlikely.
If you have a spare, or even just left and right, swap them after first removing and replacing the valves to clean the pins/socket contacts.
 
Euan said:
Doesn't sound like a valve going. They tend to go "ting" or "wheeeeee" or "crackle." Don't be afraid to open up an 834p. There's not much in it to see.

The valves in it are thruppence ha'penny. Get some spares and swap them out.
Click to expand...

Is it just the side screws that need removing to get to the tubes? Just ordered some JJs to try and they seem to get some good feedback for the 834s
 
Vinny said:
It is my understanding that going noisy is one of the commoner faults that develop with valves. That said, if it is both channels, that would be extremely unlikely.
If you have a spare, or even just left and right, swap them after first removing and replacing the valves to clean the pins/socket contacts.
Click to expand...

Thanks I'll try that, see what happens
 
If it's the 834P that looks like a brick, access is via a top plate affixed with four screws, at least on my MM only unit. Unplug it first! The board on which the tubes are mounted is quite flexible (on my unit) so wiggle tubes in and out carefully so as not to to weaken any connections.
 
brab said:
If it's the 834P that looks like a brick, access is via a top plate affixed with four screws, at least on my MM only unit. Unplug it first! The board on which the tubes are mounted is quite flexible (on my unit) so wiggle tubes in and out carefully so as not to to weaken any connections.
Click to expand...

Thanks for the guidance, really helpful.
 
So last night the EAR started making a noise like an engine idling, when my amp wasn't even very loud. It increases as I turn the amp up - sort of a burble type of noise. I put a full new set of JJ valves in, but no change, so it's definitely not a valve going. To check all the connections, I put my Soundsmith phono back in and silence.

Any ideas? I'm thinking this might be a send to EAR to be fixed job.

Cheers guys for all the support btw
 
That does sound a bit like a valve but there are plenty on here know more than me.

In terms of valves Mullard old shields or Mazdas for me. It came with JJ's and they are good but not as good.

You don't need matching for small valves I have 2 ecc82's in my pre stage and they aren't even the same make.
 
Bairnstorm said:
That does sound a bit like a valve but there are plenty on here know more than me.

In terms of valves Mullard old shields or Mazdas for me. It came with JJ's and they are good but not as good.

You don't need matching for small valves I have 2 ecc82's in my pre stage and they aren't even the same make.
Click to expand...

Thanks, pretty sure it's not the valves though. I changed the full set last night and the noise is still the same.
 
Another thing to consider when you get it working fully again is valve damper rings. My 834P sounds clearer with better resolution using them. Sprung nylon ptfe types sounded a bit dark. Herbies damper rings are my preferred type, the basic ones. A bit of a tight fit and they have to be staggered heights due space constraints. I tried alternative valves but stuck with TdP branded. Reasonable price and with dampers suited me.
 
FWIW the most likely thing is you've broken a connection/created a dry joint to a decoupling cap. look up "motorboating".
Don't be a wet with dampers:rolleyes:
 
Arkless Electronics said:
FWIW the most likely thing is you've broken a connection/created a dry joint to a decoupling cap. look up "motorboating".
Don't be a wet with dampers:rolleyes:
Click to expand...

Not sure I should be googling "motorboating" :D

I emailed EAR and they've said to post it down and they'll sort it. Probably best rather than me ramming a screwdriver into the inner workings
 
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