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Are there any other EAR 834P modders lately?

I had to beg David Schulte of Upgrade Company to mod my EAR 834P because there are so many detractors. There are also loads of DIY people who have tweaked the circuit in custom ways. The changes I had made include V-cap coupling caps and RFI shileding. Switching from using the 12AX7 tubes to 5751 or 12AT7 tubes if you can handle the lower gain also is highly beneficial. I use Valvo 6201 blue print in the one spot, Brimar and Siemen Halske 12AT7's in the gain stages 2 & 3. 2 is not left and 3 is not right- it sums the tubes for the gain stage left and right. My results are stunning. Because the 12AT7's only have 70% of the gain or the 12AX7, I changed out my Bent Audio step up tranny's for Bob's Devices Cinemag 1131 with a 1:40 or 1:20, ratio which is adjusted at the flip of a toggle switch.
zenbret
stevecham
3,340 posts
 
I replaced the three tubes with current "Genalex Gold Lions," selected for low noise (TubeDepot) and, after five years of owning and tube rolling this preowned stage, this phono pre simply sounds wonderfully magic now. Previously I had tried NOS Telefunkens, JJ standard ECC83 and ECC803s and gold pins (both selected for low noise), Tungsol, Ei regular and gold, Mullard (new version), EH, Sovtek LP and LPS (both low noise selected), as well as the stock "dPS" 12 AX7s it came with. Those Gold Lions are certainly worth the price.
zenbret OP
18 posts
 
Thanks for the info, Tfkaudio. I might have to A/B my sound with some nice 12AX7's again in the gain stage. I think I still have the Telefuncan The Fisher 12AX7's around to compare my RIAA by ear. Now that I am listening for it I can pay closer attention to how much it is skewing my balance across the frequencies. I am working out of town again tomorrow, and Saturday going to see Zappa Plays Zappa. I will post what I hear and maybe get your comments after.
stevecham
3,340 posts
 
As I have read elsewhere, in other threads, using a 12AU7 in V3 has been cited to improve bass. So last night I tried the experiement with two different 12AU7s (an EH and a JJ) in V3 (the position closest to the front of the preamp).

This did NOT improve the sound at all.

I found it to be etched and bright, and not at all improved in the bass. Replacing the Gold Lion 12AX7 brought back everything into balance and focus.
frogman
7,357 posts
 
As I mentioned in my first post, it is not the type of tube that matters as
much as wether that particular tube (in your case a 12AU7) is a good
sounding tube or not in it's own right, and complements your setup and
your tastes; as long as that variant works in a particular circuit, of course.
I find it more than a little silly that someone would suggest that 12AU7's
as a group improve bass; it's simply not the case. Having said that, the
right 12AU7 can sound very good in V3. I sometimes use a German
Amperex 12AU7 in V3 and it sounds excellent, with a very refined and
smooth, detailed sound; although not as full-bodied as my Tele 12AX7's
nor Raytheon 7025's.

Another example: I don't know how often I hear guys say that 5751's are
the ticket in this phono stage. They then go out and buy inferior 5751's,
and wonder what the hoopla is about.

BTW, the lead bars are for dampening. I never considered that they may
be help shield RFI. They just might especially considering I don't use the
cover. Regardless, I find them very effective in really tightening things up,
and improving definition.
frogman
7,357 posts
 
Stevecham, to be clear, I didn't mean to suggest you were being silly. I was referring to then references you cited. Regards.
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