What output capacitors for phono preamp

0 Members and 1 Guest are viewing this topic. Read 10277 times.

earwig

What output capacitors for phono preamp
« on: 7 Feb 2010, 06:53 am »
My Acurus phono preamp has been running with the 10uf ,200v MIT ppms metalized film Multicap at its output for a year now but they do not sound very good.The bass is cut off more at the bottom and it sounds brite.The original was a pair of yellow ECI TMPO 10uf,100v(military mylar?) that had a somewhat darkened sound but at least it had bass.E-bay has someone right now selling some VALAB Pio Oil polypropylene outa Taiwan that claim to be good audiophile quality at 10uf ,100v.Has anyone tried them or heard them here? Does anyone have a suggestion for a suitable phono preamp output cap that sounds nice?Just want to see if any audiophiles out here had some good experiance with  phono cap mods.
« Last Edit: 8 Feb 2010, 08:56 am by earwig »

rollo

  • Restricted
  • Posts: 5532
  • Rollo Audio Consulting -
Re: What output capacitors for phono preamp
« Reply #1 on: 8 Feb 2010, 11:59 am »
There are many caps to choose from. The Audio Note silver in mylar sound great. However why not look for the caps that were in there originally. Makes sense rather than hoping the characteristics of the new cap will synergize with the phono section.
  If you want a neutral cap that IMO will not impart any signature a V-cap Teflon would be my choice. Expensive and a bitch to break in. Mucho hours. Just remember that sometimes the change is NOT a guarantee of better sound, different yes better, maybe.
 My two cents. Have fun.

charles

WGH

Re: What output capacitors for phono preamp
« Reply #2 on: 9 Feb 2010, 01:34 am »
The Hagerman Cornet2 uses a couple of 1uf output caps; tubesforever has tried many different brands until he settled on Mundorf Silver/Oil which is what I and many other people used in their builds though it would be foolish to extrapolate what works for a Cornet2 phono pre-amp will also work in an Acurus and at $136 each for a 10uf Mundorf cap it would be an expensive experiment.

There are a lot of cap threads but unfortunately search results aren't linkable so do a search for "Cornet2 caps" by tubesforever

Wayne

doak

Re: What output capacitors for phono preamp
« Reply #3 on: 9 Feb 2010, 05:24 am »
My Acurus phono preamp has been running with the 10uf ,200v MIT ppms metalized film Multicap at its output for a year now but they do not sound very good.The bass is cut off more at the bottom and it sounds brite.The original was a pair of yellow ECI TMPO 10uf,100v(military mylar?) that had a somewhat darkened sound but at least it had bass.E-bay has someone right now selling some VALAB Pio Oil polypropylene outa Taiwan that claim to be good audiophile quality at 10uf ,100v.Has anyone tried them or heard them here? Does anyone have a suggestion for a suitable phono preamp output cap that sounds nice?Just want to see if any audiophiles out here had some good experiance with  phono cap mods.

10uf output caps in a phono preamp?!?!
Seems a VERY large value to me. 
I use 10uf Mundorf silver/oil in my speaker  xover. 
They are nearly the size of a drink can and quite expensive.
Would be tough to fit in most enclosures.

earwig

Re: What output capacitors for phono preamp
« Reply #4 on: 9 Feb 2010, 06:12 am »
Yes ,most of the caps are meant for tubes and are huge ,not for a $700 discreet transistor class A budjet Acurus phono amp like mine.The Clarity Cap 250v,10mf ,px series Im considering also is 45mm L x 28mm thick simular size to the originals.The Multicaps I unfortunatly put in have been reviewed to have a hard brite sound and seem to shallow out the bass they say its the !0 section constuction. I think it does sound tilted up and hard compared to the original mylars.What do you think of Clarity cap?Or the compact Valab pio oil?

oneinthepipe

  • Full Member
  • Posts: 1378
  • Trainee
    • Salk Signature Sound/Audio by Van Alstine two-channel system
Re: What output capacitors for phono preamp
« Reply #5 on: 9 Feb 2010, 06:38 am »
I don't intend to hi-jack the thread, but I have two AVA preamps, both with phono boards, and neither uses output coupling caps in either the line or phono stages. 

I thought that avoiding output coupling caps was preferable.

Aren't the coupling caps used for blocking DC?   Or did the manufacturers use output coupling caps to allow users to adjust the preamp's "sound", like tube rolling?

I did a search in The Lab, but I didn't see anything specific to phono stages.




Sorry, I inadvertently hit the wrong button and deleted the post.

earwig

Re: What output capacitors for phono preamp
« Reply #6 on: 9 Feb 2010, 12:29 pm »
There seems to be some liking to the Sonicap gen 1 in the capacitor review thread.Hmm sounds interesting.Sorry but its just the way my phono is designed built,perhaps they are designs that are better about Im sure.I just want to improove this one for now.Thanks anyways
« Last Edit: 10 Feb 2010, 01:00 pm by earwig »

earwig

Re: What output capacitors for phono preamp
« Reply #7 on: 10 Feb 2010, 06:28 am »
I think the best candidates for a solid state preamp would be Sonicap 200v,Clarity cap px 250v,Valab pio oil polyproplylene 100v,Mundorf M-cap 250v,Dynamicap E 310v so far.The EC cap is very simular to the originals I had. In a review the EC was not a very good sounding cap.What would be your favourite amoungst these?
« Last Edit: 10 Feb 2010, 12:54 pm by earwig »

BobM

Re: What output capacitors for phono preamp
« Reply #8 on: 10 Feb 2010, 01:11 pm »
The Sonicaps are nice, especially if you bypass them with a .1uF Sonicap II. Or better yet, get a .1uF Russian teflon and use that as a bypass (if you've got the room for these monsters).


NagysAudio

  • Full Member
  • Posts: 466
    • http://www.nagysaudio.com
Re: What output capacitors for phono preamp
« Reply #9 on: 10 Feb 2010, 04:12 pm »
I like the following, in that order:

ERO MKT1822
Jantzen Z Silver
Solen
SoniCap
Jensen
 
Whatever you do, do not remove these caps. I see a post above who implied such a thing and obviously the person is misinformed.

avahifi

  • Industry Contributor
  • Posts: 4698
    • http://www.avahifi.com
Re: What output capacitors for phono preamp
« Reply #10 on: 10 Feb 2010, 07:00 pm »
Hi NagysAudio,

Actually the person is NOT misinformed.  AVA new current production solid state preamps do not need or use output coupling capacitors at all.  They are absolutely DC stable even at turn on and turn off.  No need to try "capacitor rolling" to limit the damaging effects (if any) of output coupling capacitors.  :)

Regards,

Frank Van Alstine

NagysAudio

  • Full Member
  • Posts: 466
    • http://www.nagysaudio.com
Re: What output capacitors for phono preamp
« Reply #11 on: 10 Feb 2010, 07:48 pm »
Hi Frank,

OP was talking about Acurus preamp, not AVA preamp. Oneinthepipe implied that capacitors in general are not needed in the output stage and are best avoided.
« Last Edit: 2 Mar 2010, 07:46 pm by NagysAudio »

oneinthepipe

  • Full Member
  • Posts: 1378
  • Trainee
    • Salk Signature Sound/Audio by Van Alstine two-channel system
Re: What output capacitors for phono preamp
« Reply #12 on: 10 Feb 2010, 11:46 pm »
Oneinthepipe implied that capacitors IN GENERAL are not needed in the output stage and are best avoided. He/she is completely misinformed.

I didn't imply.  You inferred, albeit incorrectly.   I stated, "I thought that avoiding output coupling caps was preferable".  There is nothing implicit in my statement.  If a preamp can be designed and built without output coupling capacitors, which control DC, why would manufacturers build preamps with output coupling capacitors?  Is the purpose to permit the manufacturer or owner to "roll" capacitors to adjust the "flavor" of the sound?  Is my purported misinformation that output coupling capacitors control DC?

I am not completely misinformed, and your comment is harsh.  I assume that you are a knowledgeable person and could have responded constructively to my questions, or if my questions were off-topic, you could have merely ignored me rather than issue a warning based upon your incorrect inference followed by a disparaging comment about my knowledge or lack thereof.   

There is nothing in my questions that suggests that anyone should remove capacitors from their preamps.  Questions are requests for information rather than suggestions, notwithstanding.

earwig

Re: What output capacitors for phono preamp
« Reply #13 on: 11 Feb 2010, 08:46 am »
Yes even the original ouput caps certainly looked big on the transistor board of my Acurus,they were 1.5 x 1" the Sonicap would still fit fine they are 1.8 x 1" and I could still add on those  radioactive looking  :green: russian bypasses on it too.Most caps mentioned are large and high voltage ,great for tubes and speaker crossovers but not suitable the fit in transistor preamp.My Aragon Arum has exactly the same old caps as the Acurus has (same value too)at its ouputs.If the Acurus mod prooves successful then my Arum will be next.Heh heh heh