Good DIY Phonostages...

RE: Good DIY Phonostages..., posted on October 25, 2015 at 21:29:50
Eli Duttman Audiophile Posts: 10455 Location: Monroe Township, NJ Joined: March 31, 2000	There's more than 1. Contact "inmate" Jeff Yourison for the implementation details of his build of the tweaked RCA setup (schematic) uploaded. BTW, you'll have money left over to buy some LPs with. :>D Eli D.

RE: Good DIY Phonostages..., posted on October 25, 2015 at 23:10:49
SoundMann Audiophile Posts: 588 Joined: October 21, 2015	How does the mosfet follower affect the sound of this circuit?

RE: Good DIY Phonostages..., posted on October 25, 2015 at 23:40:15

Eli Duttman
Audiophile

Posts: 10455
Location: Monroe Township, NJ
Joined: March 31, 2000

COMPLETELY transparent! The 'X7 triode is an excellent voltage amplifier, but it "can't fight its way out of a wet paper bag". The source follower allows the phono preamp to drive the awkward 10 Kohm IHF "standard" load. The RCA original needs a minimum load of 220 K. :>(

Yes, you can DC couple a cathode follower to the 2nd gain block, but you have heater current and heater to cathode potential limit concerns. Setting the FET up is pretty much a "no brainer". "Horses for courses."

The capacitances of the ZVN0545A are tiny. Even the wimpy 'X7 triode drives them with aplomb.

Eli D.

ZVN0545A Data Sheet

RE: Good DIY Phonostages..., posted on October 26, 2015 at 05:51:44

Triode_Kingdom
Audiophile

Posts: 10049
Location: Central Texas
Joined: September 24, 2006

You'll probably get as many opinions on this as there are Asylum members. I recommend that you read the late Allen Wright's white paper on phono preamps at the link below. Then look in the "Schematics" section of his Website for the FVP5A, an updated version of the FVP5 described in his paper. You might also Google "phonodude 5755" for an interesting design using zero-bias triodes. There are also a few circuits on the Steve Bench site that members here seem to like (I haven't built them myself). There are hundreds, if not thousands, of other designs out there. Whatever you choose, I would caution that not all schematics on the Web are legitimate. Some have been cobbled together by persons who lack the qualifications to publish (as implied by the inherent errors in their work), and in some cases, individuals who apparently never actually built the circuit. Stick with well-known sources, and you'll be OK. Also note that if you're considering a kit, Bottlehead gets very high marks from its users.

http://www.vacuumstate.com/fileupload/SP_15_Article.pdf

RE: Good DIY Phonostages..., posted on October 26, 2015 at 08:23:40

SteveBrown
Audiophile

Posts: 2454
Location: Portland, OR
Joined: November 14, 2002

You would have a hard time beating Gary's:

Gary Pimm Phono

RE: Good DIY Phonostages..., posted on October 26, 2015 at 08:59:44
geezerrocket	Wow! That thing sure is pretty! How about a few more pics ?

RE: Good DIY Phonostages..., posted on October 26, 2015 at 09:37:21
SteveBrown Audiophile Posts: 2454 Location: Portland, OR Joined: November 14, 2002	I've not built it, so you'd have to ask Gary for pics, but I think it's been a long time since he has been to the Asylum. I have had the pleasure of hearing it, and it is amazing.

RE: Good DIY Phonostages..., posted on October 26, 2015 at 15:40:03
Gingertube Audiophile Posts: 545 Location: South Oz Joined: October 8, 2004	You can also look at this: http://glass-ware.stores.yahoo.net/aiphpcb.html If you have limited tube experience this would be a good way to go. Gary Pimms (see below) is excellent but is a "for experienced tube circuit builder" level project. Having said all that my best and my second best phono preamps are both op-amp designs. Cheers, Ian

RE: Good DIY Phonostages..., posted on October 26, 2015 at 16:43:02
Caucasian Blackplate Industry Professional Posts: 8313 Location: Seattle Joined: June 18, 2004	The presence of grid leak bias on the last stage is amusing and somewhat baffling. I would guess it's to avoid a cathode bypass cap? (though there are other ways)

RE: Good DIY Phonostages..., posted on October 26, 2015 at 18:06:38

SoundMann
Audiophile

Posts: 588
Joined: October 21, 2015

The Glass-Ware designs look interesting. Whether-or-not they will meet all of my sonic criteria is another thing altogether.

I prefer a good old fashion lush and harmonically rich presentation with enough air and transparency to balance it out. I find that the Ear 834p does a suitable job of it. There is currently a kit based on this circuit.

Ear 834 Phono Amplifier DIY KIT

RE: Good DIY Phonostages..., posted on October 27, 2015 at 16:08:34
SoundMann Audiophile Posts: 588 Joined: October 21, 2015	No opinions or idea's about the Ear kit?

RE: Good DIY Phonostages..., posted on October 28, 2015 at 00:47:59
neskor Audiophile Posts: 4 Joined: April 13, 2012	This one ;) valve Itch http://www.diyaudio.com/forums/analogue-source/140635-valve-itch-phono.html

Allen's work and results should get more credit-nT, posted on October 28, 2015 at 10:44:43
Cleantimestream Audiophile Posts: 7551 Location: Kentucky Joined: June 30, 2005	! The Mind has No Firewall~ U.S. Army War College.

RE: Good DIY Phonostages..., posted on October 29, 2015 at 08:09:47
Triode_Kingdom Audiophile Posts: 10049 Location: Central Texas Joined: September 24, 2006	"No opinions or idea's about the Ear kit? " If you want Chinese junk, why bother to build it? There must be something already gobbed together in your price range.

RE: Good DIY Phonostages..., posted on October 29, 2015 at 16:43:08
SoundMann Audiophile Posts: 588 Joined: October 21, 2015	Chinese junk? That would only be true if it were a finished product. We are only talking about a circuit board, and a few potentially hard to find components!

RE: Good DIY Phonostages..., posted on November 4, 2015 at 11:48:55

geezerrocket

$350 bucks.
Here ya go.....

http://parksaudiollc.com/budgiepreamp.html

RE: Good DIY Phonostages..., posted on November 8, 2015 at 00:22:58

morinix
Manufacturer

Posts: 528
Joined: October 19, 2000

I built the RCA classic once. It was really soft sounding, like an old console system.

RE: Good DIY Phonostages..., posted on November 8, 2015 at 09:51:06
lugnut1 Audiophile Posts: 132 Location: Austin,TX Joined: September 24, 2011	Morinix, What other system components did you use when listening to the RCA phono stage?

RE: Good DIY Phonostages..., posted on November 8, 2015 at 13:46:48
morinix Manufacturer Posts: 528 Joined: October 19, 2000	Straight into a modified Masterlink ML9600 with a Madrigal DAP directly driving AKG 710 headphones. The ML9600 had a 1Meg input terminating resistor (part of my mods) so it was easy for the RCA Classic to drive.

RE: Good DIY Phonostages..., posted on November 19, 2015 at 06:03:59

pix
Audiophile

Posts: 411
Location: sweden
Joined: March 18, 2006

This is my contribution

* Simple design with very few good components
* Siutable for mid output MC�s with a 1:10 SUT
* High GM/Mu first stage
* No feedback
* All triodes
* Dead quiet in a 110dB horn setup

I have�nt heard everything (who has?), but it�s as least the best sounting phono amp I have used in my system.

Tube DIY Asylum

Good DIY Phonostages...

8.25.246.163