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Hi all:I have read that there are modifications that can be made to improve this unit.
I found one article in the archives by Thorsten that outlined the changes.
I have two problems before I consider going ahead.
1. Thorsten's article is from 2002. I just bought my EAR and I assume changes may have been made since Thorsten's post
2. Even if the unit is the same, The assembly diagram or schematic that he included with his post does not seem to be available with the post.
Soooo, is there anyone out there that:
1. has experience with upgrading the latest models of the 834P (mine has the volume pot and can be used for MM or MC carts)
2. has access to the assy diagram or schematic that Thorsten posted, and could make it available to me so I could have a look and see if I am dealing with the same unit.
Thanks
wfs
Follow Ups:
The diagram in the post was basically the schematic, which should be in your owner's manual, at least it was on mine from 2000. A few other notes and suggestions. The chasis is tight as is the PCB traces, some of the mods take layout pre planning and soldering skills. Unless you are going direct into your amp and not through a preamp, take the volume control out of the circuit path. If using a MC cartidge, use a higher quality step-up through the MM. The MC transformers as nothing special. I suggest Jensens or the Peerless 4722 from JE Labs site. You can also replace the RCA jacks with higher quality ones, but getting the old one out is a b--ch. There are lots of parts quality v. price point compromizes in the EAR. the T mods make it better, but even modded, I never found mine involving. I like my modded ASUSA PP-1 better, and I am currently working on a DIY 6sl7/6sn7 base on Jeremey Epstien's design.
itchmay@webtv.com I'm abit fuzzy about the .com. Maybe .net Anyway, Mitch Singerman is the dude you want to contact. He is the US EAR certified service rep. He can do what ever mods you want for a very reasonable fee. He did my 834P a couple of years ago and after about 200 hrs of burn-in it was magical! The best thing is that if Mitch does the mods your warranty is still valid! Very fast turn around as I recall.
The circuit design has not changed AFAIK. The only differences would be some parts quality and omission/addition of some parts.If you have downloaded Thorstens modification guide then this will get you most of the way there. It is easy to locate the components he identifies but you must completely disassemble the unit and be very skilled at soldering/desoldering.
I would suggest you put at least 100 hours on the unit before making any changes. In addition, tube rolling will certainly change the sonic character of the unit. I found Mullard CV4004's in all 3 positions to be the most rewarding but YMMV and others here will recommend other tubes/combinations but it is all a matter of taste and system synergy.
I have extensively modded my 834p using Thorstens guide and the best mod you can do IMO is remove the transformer to outside the chassis. Place it in it's own shielded enclosure.
Not sure how far you want to go with it still under warranty but the choice is yours. Carefully read Thorstens guide and identify the upgrades you would be comfortable doing.
One other thing, the 834p responds extremely well to mod's and can be taken to extreme levels where it will compete with the best but it takes alot of work.
Best Regards,
i sent wfs a schemo earlier today...you got it?kenster,
after the T-mods, i realized my 834 lacked the space and power supply for what i really wanted to do - dual mono signal + choked out power supply with enough heater current to try various output tubes. i did have to make minor adjustments, but a 6H30 or 6n1p in the last stage speeds the stage up a bit more (not too fast though!!). the 5687 adds a slightly pinkish yellow tonal effect i really liked, but ultimately makes the friendly phono stage sound too pinkish-yellow intimate (if that makes sense).
a guy on another board is actually using adjustable air caps in the feedback RIAA...if and when i get a chance, thats the next thing i'm trying.
Dear C6H30 has silvery sound to me.
I will try a bunch of 6SN7 at V3 tomorrow on my built from scratch that already has the air caps. Vacuum Caps next.
Cheers
what kinds of 12ax7's are you using in positions 1 and 2? i found the 6h30 got shimmery as a cathode follower when instead of using old telefunkens or the reasonable performing sovteks or jj's, i threw in my tester EH or chinese tubes.my favorite 12au7's in that last position - completely unmarked and very frustrating to find - are fantastic in that last position in pretty much all ways. a good 6sn7 as a cathode follower might be nice.
Cheers
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