The 834P is a wonderful phonostage. Find the Thorsten’s Modification Guide:

http://db.audioasylum.com/cgi/m.pl?forum=vinyl&n=108318

 or just build one yourself. The 834PT delivers very-very good results, particularly with the punchy “cartridges”. BTW, I posted a picture of my air-phono-corrector in analog section of “My Playback”…

The caT

PS: Ah, Dima, I come up with very-very cool name for our phonostage!

deemon wrote:

Hello , Roma ! And what is the name ? I wanna make a label on my unit :-)

as the source for my linguistic inspiration I used a book that I know peaty much by hart - of the greatest book even written - the Thomas Mann’s “Josef and his Brothers”. In the first book – “The tales of Jacob”, the chapter “Of body and Soul” Mann telling about some possessed by spirits people who earn their bread by foaming at the mouth and delivering prophesies. “They were dirty, with crazed and distorted ways; children ran after them shouting ‘Aulasaulalaraula’ – in imitation of their babbling.” This word “Aulasaulalaraula” I feel would do a wonderful phonostage name. I actually was preparing it for the power amp but I will come up with something else for that beast.

:-)
The Cat

Brian Clark wrote:

I like it so much that I intend to build an "enhanced" copy a la Thorsten/Carsten for reference (and enjoyment!) before investigating the high Gm alternative (D3a + E55L or E810F )

It is hard to say. I use my built-from-scratch 834PT with ET2 transformer and they do beautifully. Generally if look at the 12AX7 form the 7788 perspective then they slow, placid like hell with no dynamic, no extremes and so on. In each and single audio-namable quality the “Aulasaulalaraula” corrector sounds more interesting but there is something, and I very much know what it is but at this point I do not know hot to achieve it, that withholds me to call the “Aulasaulalaraula” project as “finalized”. In any case, I run 834PT with racy needles (aka 103) and the high Gm corrector with blossoming and “full” needles (aka 901). I feel a need to add to my high Gm corrector one property of sound that would make it where I feel it should be. As I said before, I would not comment on the further specifics at this point.

The Cat

PS: BTW, if you built your own “Do me a favour” corrector the by adjusting the 110pF cap in EQ you might compensate in the HF deficiency of your 102. I is exactly what I am doing.

Ha-ha , Roma , it is very good ! ;-) I will make a good copper plate with this name and attach it to my phonostage ....... ;-)

Dima

hI bRIAN,

Brian Clark wrote:

The 834P was a revelation for me, being a circuit that I would have dismissed as "old hat" (Feedback? 12AX7 cathode follower? Do me a favour!).

Me too, but you know me, i'm mainly pragmatic. The EAR 834P is rather better than one would think, even with cheap parts, a testament to the skills of TdP.

Brian Clark wrote:

I like it so much that I intend to build an "enhanced" copy a la Thorsten/Carsten for reference (and enjoyment!) before investigating the high Gm alternative (D3a + E55L or E810F ) My step-ups will be S&B.

If you do, do seek out old Air dielectric AM tuning Capacitors. You only need 110pF & 330pF, both can be found suitably. Once you tuned the RIAA to perfection simply superglue the shaft in.... I used to use that trick in prototyping in the old days when tuning Op-Amp compensations and found circuits sounded better with those "Air Variable" capacitoirs than they did with good quality polystyrene for stabilisation.

Ciao T

Thorsten wrote:

If you do, do seek out old Air dielectric AM tuning Capacitors. You only need 110pF & 330pF, both can be found suitably. Once you tuned the RIAA to perfection simply superglue the shaft in.... I used to use that trick in prototyping in the old days when tuning Op-Amp compensations and found circuits sounded better with those "Air Variable" capacitoirs than they did with good quality polystyrene for stabilisation.

Brian,

I sourced the air caps from here:

http://www.oselectronics.com/ose_p96.htm

The AVC150 does a wonderful 110pF (I run it 112pF) and the BC14400 does good as 330pF. I did not lock them up but I do not shake them. The AVC150 has very stiff shaft, the BC14400 is very loose. However, I did not see that it drifted, although the corrector once was flying around in my car.

The only thing that you might want to do would be does not let the signal go via the bearing of the shat. In order to do so you would need to solder one contact to the default leg, however theanother one - do not connect to the chassis of the cap but to solder it to the movable plates. They are aluminum (you won’t find any cupper-made variable caps for 350pf) but with a strong solder gun (I use 200W) and long heating the thin aluminum will be solderable. Put some solder in the topmost movable plate, melt it, dial in the correct position of the shaft and then accurately solder a thin wire.

Be advised that although the 110pF EQ HF and 330pF EQ LF but it work reversing for sonic benefits. Changing of 110pF form polystyrene of mica to air (with the same value) will severally affect the quality of bass. Changing the 330pF form polystyrene of mica to air will very-very-very-very strongly affect the cleanness of HF and upper mid range.

Be carefully through, if you try those air caps once and recognize what they could do then you will stick them everywhere! I’m sticking them into my power amps, in any unnecessary and all-imaginary places, I try them on Cat and how I am working on a problem of a permanent attachment of those caps into my woman. I hope she will “sound better” after that… :-(

The caT

Hi All,

103 or 103R + mass loaded SME headshell + 3012 or a 3009 + Seiki 1500 + hagerman opamp phono stage (good only with select parts and battery power) or an EAR 834 (with some mods) and some old Altec mic transformers.  In that environment, it works quite ok...its quite a bit "harder" sounding on the opamp stage, but almost too slow on the 834. 

On either phono stage in any setup, I don't enjoy the higher frequencies.  They have a fairly improper spatial structure as compared to what I want/expect a cartridge to do.  This improper structure filters down and screws with mids too much for this to be for me the "end-all" cartridge.  This structure isn't so much an issue of "imaging" as its understood, but a lack of contrasty timber.  I want to say its too flat in tone, but that wording is too strong for my tastes.  On the other hand, an old Koetsu Black I had in this same setup (no heavy headshell), was WAY too imbued with an audible hue.

Since I often don't have the time (sometimes inclination) to alter sub 100% satisfactory results, I just keep playing the music I want without being too finicky.  Doing that, the plain 103 seems to distract me less than the 103R, but only with the opamp stage.  The 103R works better in those higher frequencies, but only well enough through the 834P.

They're both "good enough" cartridges for most people, and in the real world, a 200 buck cartridge that performs this well will make many people happy.  But that def should NOT preclude thinking on "what could be".

Your results may vary, but not by much :-)

Thinking what could be,

Chirag

BTW, my unbacked up HD crashed last week...can someone send/link me an 834P schema?  It would be rather appreciated.

Hi,

Chirag wrote:

103 or 103R + mass loaded SME headshell + 3012 or a 3009 + Seiki 1500 + hagerman opamp phono stage (good only with select parts and battery power) or an EAR 834 (with some mods) and some old Altec mic transformers.  In that environment, it works quite ok...its quite a bit "harder" sounding on the opamp stage, but almost too slow on the 834.

The EAR 834P is due to the use of "slow" and "veiled" sounding valves (ECC83's) a bit on the soft, slow and foggy sinde of the sound. That said, in many commercial (non-DIY) setups that is probably an asset.

Chirag wrote:

This structure isn't so much an issue of "imaging" as its understood, but a lack of contrasty timber.  I want to say its too flat in tone, but that wording is too strong for my tastes.

I have used the term "literal" previously to describe the 103. It is ultimatly more of a "truth" than "beauty" cartridge, no doubt a result of it's primarily pro heritage and one trait that actually agrees with me, due to also some pro background.

Chirag wrote:

They're both "good enough" cartridges for most people, and in the real world, a 200 buck cartridge that performs this well will make many people happy.  But that def should NOT preclude thinking on "what could be".

Absolutely agreed. I do not suggest that the 103 should be the only catridge you can have, but if you told me I can from now on only keep a SME 3009/10/12 Arm and Denon 103 on my turntable you probably do not get all that many complaints either.

I'd probably still prefer more choice, as I feel that as of now I have yet to hear "perfect" playback, so often it is preferable to have several arm/cartridge combo's available that have very contrasting sonic attributes and often cost all together less than top notch current "High-End" arms & cartridge combos and used judiciously can give better results for more records than a single combo

Chirag wrote:

BTW, my unbacked up HD crashed last week...can someone send/link me an 834P schema?  It would be rather appreciated.

You can e-mail for the original scan, otherwise look here:

http://www.jogis-roehrenbude.de/Leserbriefe/Carsten-RIAA/Carsten-RIAA.htm

This has a different powersupply and misses the component designations.

Ciao T

Chirag,

I have some other guys who were asking about the 834P schematic. I just got home and made a picture of my manual with the schematic in it. I do not know if it’s legal. It sort of none-commercial site and I did paid long time ago for my first unit and for the manual…  Besides, I have seen this it in many places around the web…

Anyhow, I would like to preface the image posting stating that the schema below is an intellectual property of EAR/Yoshino LTD.

Romy the Cat wrote:

Brian, I sourced the air caps from here: http://www.oselectronics.com/ose_p96.htm ... I am working on a problem of a permanent attachment of those caps into my woman. I hope she will “sound better” after that… :-( The caT

Hi Guy,

I know what you mean; this phono stage really should not work well at all.  I mean, voltage doubler, 3 stages of 12ax7, feedback, cathode followers, garbage looking power supply shared tubes for stereo...mortifying isn't it!  These facts actually kept me away from purchasing it for quite some time. OTOH, now I feel like this case, circuit boards, power supply and output tube can all be improved upon.

How about all of the T mods, Romy's air caps, a 6C45 6H30 6C19 type output tube with anode loading, external PS with bridged fast diodes, inductors and CRCRCR type dual power supply, inductors on a new parallel based heater supply, dual mono channels....goes on and on....no idea how all this would work though and it will definitely require some new cases.

Best,
Chirag

It's polishing a turd though isn't it? I listened to the 834 quite a bit when it came out and thought it sounded poor, even for the price. imho, The circuit's just bad.

If you do all that to it it isn't really an 834 anyway.

I used to work for a valve amp making company and we had a little 2 stage phono amp that sounded far better than the 834 with passive eq, no feedback etc. It also cost less than the EAR.

I can send you the schematic if you want to see it.

Hi Guy,

HAHAHA! yeah, I can see how you can say its similar to burnishing fecal matter.  i still think its overly pleasant slow sound (which is still ok through my headphone setup and denon 103) can be improved upon with major supply changes, but i'm not about to invest too much time doing it (not that i have any to waste).

Its quite a nice offer for the 2 stage schematic; my email can be accessed through my profile.

Best,

Chirag

guy sergeant wrote:

I used to work for a valve amp making company and we had a little 2 stage phono amp that sounded far better than the 834 with passive eq, no feedback etc. It also cost less than the EAR.I can send you the schematic if you want to see it.

guy sergeant wrote:

It's polishing a turd though isn't it? I listened to the 834 quite a bit when it came out and thought it sounded poor, even for the price. imho, The circuit's just bad. If you do all that to it it isn't really an 834 anyway. I used to work for a valve amp making company and we had a little 2 stage phono amp that sounded far better than the 834 with passive eq, no feedback etc. It also cost less than the EAR.

Guy, I would respectfully disagree with you about the 834P. Some people “who know” taught me about the benefits of open loop EQ in the feedback circuits. In the 834P the nature of the 12AX7 actually performs the necessary open loop EQ. There are many other thing in 834P that makes it attractive, however I certainly not a person who would dispute the circuitries….

Being a user, I have to tell that I do like the 834P. I like it either in it’s default unspoiled version, either as the Thorstened 834PT (which is way better). 834P certainly should have OK tubes in it, have no output attention and must not use the default EAR step-up transformer. Everything else, no mater how cheap and primitive it is would actually be capable to delivery very-very good result. Combined with a very good transformer I feel that it is one of the most musical phonostage I ever come across.

Pay attention, Guy, I’m not project how it performs based of my assessment of the circuits or after a few listening sessions but rather after years of living with it and years of RETURNING to it after many other, even better phonostages. Certainly there are many different solutions and methods how we can get deferent audio properties better then 834PT does. However, how necessary is it? I sincerely feel that 834PT do is absolutely enough for 95% installations and for 99.99999% of the listening musical demands. It is possible to push the envelope further but it is mostly unnecessary. I’m not kidding: I personally have a number of the phonostages but I would be perfectly fine to live with my ET2-2x834PT. Also, some other my phonostages do better in certain aspects but I still am not going to remove the 834PT from the active duty. It has something within it that is very right. It would be interesting if you elaborate on your vision were the 834PT is falling out performance-wise

In the end, one more comment in response to you post. I do not know why, but the became fashionable recently passive EQ, no feedback phonostages do not do a lot to me. Among what I heard form them they were all flat, with no space. The RLC passive were another story, however…

Rgs,
The Cat