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Home » Analog Playback» The last phonocorrector: “End of Life" Phonostage (311 posts, 15 pages)

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	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	Where are our good phonostages?..	Omnigon Tubes...	Analog Playback Forum	61	662891	05-31-2004
»	New	The Expressive Technologies SU-1..	“too bright” or “resolution” or “details” with SUT prim...	Analog Playback Forum	33	374781	12-30-2004
»	New	EAR 834P Modification Guide..	The cap will not change volume in the pass band...	Analog Playback Forum	45	636759	02-09-2006
»	New	My Analog Playback: the fat lady has sung..	My analog setup update....	Analog Playback Forum	9	119026	04-04-2006
»	New	Phono stages with SU-1..	SU-1...	Analog Playback Forum	4	65845	11-23-2007
»	New	Chasing utopian better phono interconnect...	Did I miss something?...	Analog Playback Forum	6	110460	06-05-2008
»	New	Buying a last cartridge...	Lucky you...	Analog Playback Forum	80	807213	09-05-2008
»	New	EAR 834P mods..	The cap will not change volume in the pass band...	Analog Playback Forum	45	636759	11-04-2008
»	New	AMR PH-77: just another phonostage or more?..	Oh, yeah... the sound of the Thing Itself......	Analog Playback Forum	11	131785	07-05-2009
»	New	An interesting Russian pnonocorrector...	Uber-tweeky phono topologies deconstructed...	Analog Playback Forum	9	98891	03-01-2010
»	New	Expressive Technologies SU-1 and cartridge output and i..	MV and Ohms...	Analog Playback Forum	2	33468	07-07-2011
»	New	How to run MM-type cartridge into MC phonostage?..	Quite interesting....	Analog Playback Forum	6	67040	11-13-2011
»	New	The tales of two phonostages: Allnic and 834PT...	The tales of two phonostages: Allnic and 834PT....	Analog Playback Forum	0	23295	12-21-2011

02-09-2012

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	201
Post ID:	17807
Reply to:	17805

Fight Fire with Fire?

N-set, yes, the unwanted capacitance of the big L is potentially a noisy nuisance. Without referring back to your schematic, I wonder if to set/bleed the tank with - a cap - before R/ground, a' l' Axiom? I think this is perhaps the most elegant aspect of the Axiom idea I saw (but never heard...), an idea that includes a "tiered" tank/ground system.

Another thing might be to let the L be a smaller part of the equation...

Keep complaining; I'll keep shoveling...

Best regards,
Paul S

02-09-2012

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	202
Post ID:	17808
Reply to:	17807

TT Rider

Another thought (sorry...): Did you say a while back that you ground your TT to the pre's neutral/signal ground!?! If yes, maybe try docking that MOTOR somewhere else, preferably upstream. Otherwise, why not ground the effing washing machine (or refrigerator) there, too? If the TT is grounded to the phonostage signal ground, and if the idler sports a solinoid, it must have a mute, or surely it sounds like a bomb via the phono stage?!

Best regards,
Paul S

02-10-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	203
Post ID:	17810
Reply to:	17808

Snubbers and motors

Thanks for your thoughts Paul. The subject of the snubber has already been quite discussed.
IIRC Romy has turned the whole idea down as uncessary in his context. I am afraid that
a snubber may be a sonic move rather than only "engeneering". I'll first try to learn my 834 as it is,
and only then try to experiment with snubbers a la Jim Hagerman from Hagtech--fighting the specific
resonance and not blindly shooting "just in case".

Motor: I have to check where it is connected in my EMT and if it's possible to eventually ground motor elsewhere.
Right now it's like you say: whole TT is connected to the signal chassis bolt, where also signal ground (Cu plate)
comes via a GND lift switch.

Cheers,
N-set

Cheers,
Jarek
STACORE

02-10-2012

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FJC Corpas
Madrid-Spain
Posts 4
Joined on 02-08-2012

Post #:	204
Post ID:	17811
Reply to:	17800

Nice idea...

I calculated the whole circuit and it looks each channel draw a total of about 3mA (could be even somewhat less). The second and third stage works like a whole and it´s very curious because I have seen this design before only in guitar amps in order to get a creamy sound (second order distortion). Obviously, in this case the values have been very smartly chosen (big load) to get a very interesting balanced sound . I assume this last stage transforms the phonocorrector in a different animal than the TdP design. Good job!

N-set wrote:

PS if you want to have a separate supply resistors for two channles they should be 12k, 6k is for both channels.
you can have a look at the actual schematics of my copy.

N-Set, I don´t understand why I should use two 12K resistors (one per channel) instead two 6K. I´m using a stereo PS that split the current after the 0A2 tubes through two 6K resistors. Each channel will draw about 3.5mA, and I need about 280V in the B+ of the second/third tube. All look be ok for me…

02-10-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	205
Post ID:	17812
Reply to:	17811

B+

IIRC, 6k was when you feed both channels through it, but given the currents maybe it does not matter.
The target was 270V on B+ and I got it with
two 12k as I wanted to separate the channels after the 0A2, just like you say.
Cheers,
nset

Cheers,
Jarek
STACORE

02-10-2012

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	206
Post ID:	17814
Reply to:	17812

Shielded Interconnect

N-set. do any of your interconnect shields "float"? If this is the case, I recommend bleeding them on the "upstream" end of each shield. This is another case where conductive mass = capacitance = noise. It does seem like this sort of noise would pulse, too, once the charges are sufficient to dis-charge via your so-low-R "ground plane", or adjacent inductive sink, as the case may be.

Sorry to dribble it in, but long hours and ADHD work against proper attention...

Best regards,
Paul S

02-13-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	207
Post ID:	17824
Reply to:	17814

IC shields

Paul, so far the interconnect shields were connected to the phono pre grounding bolt only--I do not want to pass
any equalizing currents between the TT and the phono via the shields (the TT chassis, armtube, etc was
connected to the same place via a dedicated wire).
The ground plane is connected to that bolt
in a star-like manner, so given a direct DC path to the earth or the ground plane I hope the noise will pick the direct path.
Now I've cooked an interconnect which is double shielded so I can experiment with shiled
connections--outer, more noisy to the TT, inner to the phono, etc.
Cheers,
Nset

Cheers,
Jarek
STACORE

07-14-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	208
Post ID:	18395
Reply to:	17824

The horrors of calibration

I'm pathetically slow with my 834 clone, but that's what I am....
Sorry for boring you but I treat this threat a bit like a blog on my "progress".
I've tried to fight more with PS induced ham and interference
by putting the PS transformers and HV rectifiers into steel tombs (pics below)
Did not help much, 5-7dB lowered the noisefloor, but did not remedy 100Hz and harmonics realted to HV operation.
Still, the ham free operation is when the PS is far away...I can't help the fact
that I'm floating in my apartment, all my efforts to find the earth failed...my HP400L
milivotmeter also did not want to operate below 3mV range in my flat (while runs perfectly
well in my friend's who has the earth).

I've also put better tubes: Telefunken(good used)-Sylvania(new)-Telefunken(good used) as a KGS (known good solution).
The noise floor did not drop compared to chinese 12ax7 I've been using so far. Sylvania is crazy...sort of....
at -1.05V bias it has 90-100V on the plate instead of 150V...to hell with that.

I've moved to calibration finally. I used Hagtech's iRIAA, I know it's a bit off at HF (and will try to remedy it
per Jim's instructions, need 6.2nF cap), but I wanted a
coarse calibration first. I managed to get a +/-0.3dB "flat" resp:

The HF roll-off is (mostly) due to my soundcard (Shit Blaster X-Fi or sth like that). Measured with a HP selective voltmeter
with 50R driving impedance, Tribute iron that I use showed -1dB at 50kHz. The LF roll-off is another problem...probbly Pieter wanted more HF,
assuming low imp. source. I have no idea what's Jim's iRIAA output imp. 50R?

The things went much more ugly when I used HFNR test LP and swept 20-20k. What was once "flat" had a huge bump at 10k.
So I have reaclibrated 834 to ameliorate it. Still, the effect is poor:

The spikes are dust/static artefacts, not important.
The LF rolloff is -3dB at 30Hz....bye bye lower bass...Pieter probably ignored my alerts that TSD15 is high impedance at 24R
and wound his standard. Then the HF horror...the cart is loaded as per EMT recommendations: 82k through 1:20 giving 200R at the cart.

I have too little experience to find a way out. Any ideas why the heck it's so ugly?
1) Shall I calibrate the 834 separately, without the cart, using e.g. iRIAA and make it as flat as possible
and then fight cart resonance with loading, or
2) Calibrate the phono-cart as a whole?

Here is some diy porn,mostly for my reference:

PS trannies in their tombs

HV rectifiers in their tomb...rest in hell with your RF garbage

DIY intershitconnect. Twisted cardas pair in teflon tubing, then heavy braid at each channel, heatshrink,
second braid on both channels, Vampire CU RCA plugs and amphenol 7pin to connect to EMT929 arm.
The master of stiffness, whoever worked with cardas knows what I'm talking about:

Connecting securely to the amr with that stiff kielbasa was a noghtmare, I fitted two adjustable bands, connected by 3 pieces of a steel wire. Works good:

Cheers, Nset.

PS I use iRIAA fed with pink noise to burn in the SUT's. The level at the SUT's secondaries is 10mVpp

Cheers,
Jarek
STACORE

07-14-2012

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	209
Post ID:	18397
Reply to:	18395

Floating Away

Man, I really wish you could just enjoy this thing!

Difficult even to imagine that NOTHING in your apartment is grounded. The only way I know of to get away with "no ground" is with batteries, and in my own case I still bleed the IC shields/chassis to a dedicated ground.

I think I have already asked repeatedly, but is the entire chassis part of the "ground plane"? If so, perhaps less mass would help?

Best regards,
Paul S

07-15-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	210
Post ID:	18401
Reply to:	18397

Ground is +/- understood

Paul, with my semi-nomadic life I don't have much chance to work on what I want to work on...

The grounding etc I have +/- understood. What now is beyond me is cart-phono interaction and calibration.
How do you calibrate your phono?

Cheers,
n-set

Cheers,
Jarek
STACORE

07-15-2012

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	211
Post ID:	18403
Reply to:	18401

"Calibrate"???

N-set, if you have an unused circuit in the apt., then its neutral may be an acceptable ground path (neutral stays "on" even when breaker is "off"...).

Re, the phono calibration, I have expounded the SRA at length in the "Vinyl Ceremonies" thread. As for tuning the gain stage(s), I'm afraid this can only be done by ear when all else is well. As for the cartridge "loading", I started out with a "made-for-each-other" cartridge/SUT pairing and went from there to a standard 47k Ohm "mm" level of gain, since I prefer the SUT to extra active gain.

Anyway, I hope your RIAA is dialed in, so you are not asking about this!

Best regards,
Paul S

07-16-2012

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Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	212
Post ID:	18404
Reply to:	18403

The self-serving calibrations.

n-set, I think the precisions of calibrations that are trying to accomplish is absolutely irrelevant and in a way self-serving. Individual cartridges have huge frequency deviation and the way how individual LPs were cut has huge frequency deviations. You are fighting for .2dB but you will find LPs with 10-15dB peaks in HF, suck out at LF or just EQ at midrange. I know the RIAA maker love to advertise some kind of high precision of RIAA response but it is absolutely irrelevant. Not the last factor is that many LPs were cut without using RIAA standard but using many of other EQ standarts.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

07-16-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	213
Post ID:	18406
Reply to:	18404

Fighting with RIAA

I'm precisely fighting with dialing-in the RIAA....
I tried to follow (parts of) Romy's description earlier in the thread, but the anti-RIAA method
and test LP give me a huge difference, much bigger than 0.2dB (rather 10dB or so):
what was +/- flat using anti-RIAA becomes awfully peaked at 10kHz using cart+test LP.

So I'm wondering how to dial in the RIAA? Using the actual cartridge and correcting for
it's resonances/SUT intercation in the phono
or make the phono as flat as possible without a cart?
Those two methods in my case give diverging results.

Cheers,
N-set

Cheers,
Jarek
STACORE

07-16-2012

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	214
Post ID:	18407
Reply to:	18406

The Usual

N-set, the usual way of dialing in RIAA is the anti-RIAA curve, trying for null. This might be from any source with appropriate output voltage/impedance fed to the corrector input. The obvious problem with the LP is that it depends on the arm and cartridge set-up, as well.

I hope you have a trim-able cap or R in the circuit, or some way to avoid soldering parts in and out! I have seen but not tried special "plug-in" jacks for the Vishay S102s, maybe use some grease. Unfortunately, the corners are hard to check, due to "moving target" reality, versus static "model" values. OTOH "good enough" really is in this case, and there are, after all, so many other variables in the phono repro chain.

Best regards,
Paul S

07-16-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	215
Post ID:	18408
Reply to:	18407

That's it!

Ok, Paul, this is the info that I needed, thank you!

My Hagtech anti-RIAA has 50R output imp. at -60dB output for MC.

Unfortunately my load resistors are soldered and in a very painful place,
(for some reason the circuit did not accper the loading R at the transformer secondary directly
but wanted at the tube socket...otherwise more ham...) but I'll definitely experiment with various
loadings, placed on the primary, secondary and both.

Cheers,
N-set

PS I think I know what Romy meant by "lush" Wink

Cheers,
Jarek
STACORE

07-16-2012

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	216
Post ID:	18409
Reply to:	18408

Parts Location

N-set, at the socket is usually the best place for tube-specific parts, and straight undernerath the socket is often the quietest at-the-tube location. Sorry if your socket connections are hard to get to. Again, I think someone makes a nice "socket" for the Vishay S102, and similar R leads, or you might use an adjustable wire wound and note the (jumped) value at null, rather than soldering parts in and out for a couple of pF!

"Lush" means "an abundance" of (2nd) harmonics!

Best regards,
Paul

07-17-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	217
Post ID:	18410
Reply to:	18409

Lush layout

Paul S wrote:
N-set, at the socket is usually the best place for tube-specific parts, and straight undernerath the socket is often the quietest at-the-tube location.

Yes, this is my exp. too, although loading R has two roles here: 1) loading the cart/SUT 2) providing grid to ground path for the 1st stage

Paul S wrote:

Sorry if your socket connections are hard to get to. Again, I think someone makes a nice "socket" for the Vishay S102, and similar R leads, or you might use an adjustable wire wound and note the (jumped) value at null, rather than soldering parts in and out for a couple of pF!

I've never seen a Swiss watch maker at work, but I'm pretty sure I could compete with one after few soldering/desoldering of my R_load...
all is the price for my idiocy when layig out..obviously for dil-in I'll just put the R on the most convenient location (directly at te SUT).

Paul S wrote:

"Lush" means "an abundance" of (2nd) harmonics!

Hard reading cart! I'm wondering what's interesting out there, more agressive than my TSD15SPH...and in the same price range.

Cheers,
Jarek
STACORE

09-03-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	218
Post ID:	18566
Reply to:	15648

Pinging Stitch/Syntax

So you showed off with your rocket radar something called Omni Gone here:

http://www.whatsbestforum.com/showthread.php?6068-Omni-Gon-The-Final-Phonostage

What caught my attention is the switching of the phono inputs (since there are multi SUT's
on board I guess it's done at the secondaries rather than primaries, sth. I want to implement).
I spied a bit and found you mention TKD parts. A bit of a search and probably the phono
switch is TKD 2R6A:

http://www.tkd-corp.com/pdf/p05_2r6a.pdf

Quite impressive, also price-wise but not unreasonable given the other choices (urine/mercury wetted relays etc).
You are most probably well familiar with all your components, so how would you comment
on the "performance" (in lieu of a better word) of the phono switch ? Can it be the panacea for the
phono switching?

Thanks,
N-set

Cheers,
Jarek
STACORE

09-03-2012

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	219
Post ID:	18567
Reply to:	18566

It might be very impressive

Thank for the link. I did not see it is it does look interesting. II like those crazy, unreasonably-obnoxious, no hold barred projects and they usually do push the envelope of what is possible. I did not have a chance to read the whole thread. We have a long Labor Day weekend in US and I am at Cape Code beach, trying to convince the hungry local shark that I am not a seal. I have connection but the sun makes reading unpleasant. I look forward to read and specifically to look at the schematic as I get back to the main land.

About the TKD switched – it is hard to say. One need to run the direct wired against the switch and convinces itself that the switch has no auditable impact. The better cartridge, cable, phonostage and the rest of system are the more complicated to do it.

The caT

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

09-03-2012

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	220
Post ID:	18568
Reply to:	18567

To be clear

The Stitch/Syntax showing-off Bavarian inhabitant is to be blamed for this monster radar rocket 100% in-law-with-physics sumo something.
Me is only fighting with my Pussy EAR834...only 16kg so, I'm a small boy Smile

Very to-the-point remark regarding "visibility"!
Unfortunately the price tag of 200Eu is a bit too much to e.g. find that it's audible.
tTHis sumo radar amp is supposed to be the best of the best of the best (=Bavarian, of course), hence my question to Stitch.

Endless options: TKD, Shallco, Seiden, Urine-wetted, ...fuck, how much I hate it!

PS Is this Labour Day a US version of Pervoe Maya (1st of may)?

Cheers,
Jarek
STACORE

Page 11 of 16 (311 items)

Select Pages:

« First ... « 9 10 11 12 13 » ... Last »

	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	Where are our good phonostages?..	Omnigon Tubes...	Analog Playback Forum	61	662891	05-31-2004
»	New	The Expressive Technologies SU-1..	“too bright” or “resolution” or “details” with SUT prim...	Analog Playback Forum	33	374781	12-30-2004
»	New	EAR 834P Modification Guide..	The cap will not change volume in the pass band...	Analog Playback Forum	45	636759	02-09-2006
»	New	My Analog Playback: the fat lady has sung..	My analog setup update....	Analog Playback Forum	9	119026	04-04-2006
»	New	Phono stages with SU-1..	SU-1...	Analog Playback Forum	4	65845	11-23-2007
»	New	Chasing utopian better phono interconnect...	Did I miss something?...	Analog Playback Forum	6	110460	06-05-2008
»	New	Buying a last cartridge...	Lucky you...	Analog Playback Forum	80	807213	09-05-2008
»	New	EAR 834P mods..	The cap will not change volume in the pass band...	Analog Playback Forum	45	636759	11-04-2008
»	New	AMR PH-77: just another phonostage or more?..	Oh, yeah... the sound of the Thing Itself......	Analog Playback Forum	11	131785	07-05-2009
»	New	An interesting Russian pnonocorrector...	Uber-tweeky phono topologies deconstructed...	Analog Playback Forum	9	98891	03-01-2010
»	New	Expressive Technologies SU-1 and cartridge output and i..	MV and Ohms...	Analog Playback Forum	2	33468	07-07-2011
»	New	How to run MM-type cartridge into MC phonostage?..	Quite interesting....	Analog Playback Forum	6	67040	11-13-2011
»	New	The tales of two phonostages: Allnic and 834PT...	The tales of two phonostages: Allnic and 834PT....	Analog Playback Forum	0	23295	12-21-2011