EAR 834P needing repair

Paul Ebert · 27th December 2007, 09:23 PM

I have an EAR 834P that has developed distortion on the left channel. It only occurs on certain relatively high frequency sounds. I've replaced the tubes but that didn't help.

Anyone able (and willing) to help me fix it? If anyone had a schematic they'd be willing to share, that would be a good start.

Based on my experiences (not with EAR, but with commercial audio components in general), I'm not very enthused about sending it to a dealer for repair. If I cannot fix it, I'll probably build a solid state phono preamp (maybe the PhonoClone).

Thanks!

HollowState · 27th December 2007, 09:37 PM

Quote:

Originally posted by Paul Ebert
If I cannot fix it, I'll probably build a solid state phono preamp.

Egad man....that's heresy!

analog_sa · 27th December 2007, 09:57 PM

The circuit is well known and extremely simple. Shoot me a PM and i'll email it to you. It may be a defective passive component or even a bad socket.

analog_sa · 27th December 2007, 10:14 PM

Or much better have a look here

SY · 27th December 2007, 10:46 PM

Hmmm, no schematic at that link. Not much real info, either. Is this the cascode pre?

korneluk · 27th December 2007, 11:04 PM

The EAR834P schematic can be found here:

http://bbs.hifidiy.net/viewthread.ph...id%3D10&page=2

and here:

http://www.audiocircle.com/gallery/d...lbum=546&pos=0

Enjoy,

-- josé k.

SY · 27th December 2007, 11:18 PM

Jose, thanks. Interesting.

Paul Ebert · 29th December 2007, 01:19 PM

Thanks for the help. I think I'll, at least, take a stab at fixing it. It doesn't look too complicated.

Any suggestions on how to start? I suppose I could start making Thorsten's mods and see if I end up replacing the faulty component.

SY · 29th December 2007, 01:26 PM

It's generally a bad idea to start modifying something that isn't working. Fix the problem first, then you can start spending money on random fashion componentry.

I'd start by measuring the plate and cathode voltages of each stage and indicating them on the schematic. Compare them between channels.

Paul Ebert · 29th December 2007, 01:38 PM

Yeah, I can see what you're saying. I'll give that a try.

Thanks.

27th December 2007, 09:23 PM	#1
Paul Ebert diyAudio Member Join Date: Mar 2003 Location: Central NY	EAR 834P needing repair I have an EAR 834P that has developed distortion on the left channel. It only occurs on certain relatively high frequency sounds. I've replaced the tubes but that didn't help. Anyone able (and willing) to help me fix it? If anyone had a schematic they'd be willing to share, that would be a good start. Based on my experiences (not with EAR, but with commercial audio components in general), I'm not very enthused about sending it to a dealer for repair. If I cannot fix it, I'll probably build a solid state phono preamp (maybe the PhonoClone). Thanks!

27th December 2007, 10:46 PM	#5
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	Hmmm, no schematic at that link. Not much real info, either. Is this the cascode pre? __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

27th December 2007, 11:18 PM	#7
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	Jose, thanks. Interesting. __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

29th December 2007, 01:26 PM	#9
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	It's generally a bad idea to start modifying something that isn't working. Fix the problem first, then you can start spending money on random fashion componentry. I'd start by measuring the plate and cathode voltages of each stage and indicating them on the schematic. Compare them between channels. __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

27th December 2007, 09:57 PM	#3
analog_sa diyAudio Member Join Date: Aug 2002 Location: Sofia	The circuit is well known and extremely simple. Shoot me a PM and i'll email it to you. It may be a defective passive component or even a bad socket.

27th December 2007, 10:14 PM	#4
analog_sa diyAudio Member Join Date: Aug 2002 Location: Sofia	Or much better have a look here

27th December 2007, 11:04 PM	#6
korneluk diyAudio Member Join Date: Jan 2005 Location: South Florida	The EAR834P schematic can be found here: http://bbs.hifidiy.net/viewthread.ph...id%3D10&page=2 and here: http://www.audiocircle.com/gallery/d...lbum=546&pos=0 Enjoy, -- josé k.

29th December 2007, 01:19 PM	#8
Paul Ebert diyAudio Member Join Date: Mar 2003 Location: Central NY	Thanks for the help. I think I'll, at least, take a stab at fixing it. It doesn't look too complicated. Any suggestions on how to start? I suppose I could start making Thorsten's mods and see if I end up replacing the faulty component.

29th December 2007, 01:38 PM	#10
Paul Ebert diyAudio Member Join Date: Mar 2003 Location: Central NY	Yeah, I can see what you're saying. I'll give that a try. Thanks.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
My own version of the EAR 834P Clone	Algar_emi	Tubes / Valves	43	8th July 2010 02:49 PM
Anyone interested in building an EAR 834P?	mattjk	Tubes / Valves	6	29th June 2010 05:27 PM
GAS Thoebe Preamp Needing Repair	civildan	Solid State	26	30th December 2009 02:58 AM
ear 834p output resistance	FTSIKIS	Tubes / Valves	5	10th May 2007 09:26 AM
Audyn-Cap MKP-QS 400V for EAR 834P ???	Raphael1	Analog Line Level	2	1st October 2006 03:02 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read