My first phono pre - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 4th December 2014, 09:57 PM   #1
diyAudio Member
 
Join Date: Mar 2008
Default My first phono pre

I plan to build phono pre with E180F (TESLA gold pin) for Shure M 75. Hammond 126C I have in stock. I know it would be better to use Lundahl. I will use Russian Silver Mica capacitors (SGM Series). For power I plan to use 2x Salas SSHV2. I ask for comments.
Attached Images
File Type: png PHONO PRE.png (15.0 KB, 486 views)
  Reply With Quote
Old 4th December 2014, 10:10 PM   #2
diyAudio Member
 
Join Date: Feb 2010
Location: Helsinki
Just out of curiosity, why did you choose that tube?

Russian silver micas are the best caps for filters, absolutely.

If you're going to have SS regs (smart choise), why not have a source follower as output? Certainly it'll be best for whatever cable loads there might be. Could also double as a plate load.
  Reply With Quote
Old 4th December 2014, 10:28 PM   #3
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally Posted by MrCurwen View Post
Just out of curiosity, why did you choose that tube?

Russian silver micas are the best caps for filters, absolutely.

If you're going to have SS regs (smart choise), why not have a source follower as output? Certainly it'll be best for whatever cable loads there might be. Could also double as a plate load.
I like the sound of E180F in triode or in pentode mode. It also has right MU (around 50) for Phono pre. Source follower - you mean add another tube and one cap?
  Reply With Quote
Old 4th December 2014, 10:49 PM   #4
diyAudio Member
 
Join Date: Feb 2010
Location: Helsinki
I mean something like this.

CCS is optional, but it does improve performance.

Source follower doubles as a great plate load for the tube for best performance.
Attached Images
File Type: png source follower output.png (15.5 KB, 466 views)
  Reply With Quote
Old 5th December 2014, 08:24 AM   #5
Merlinb is offline Merlinb  United Kingdom
diyAudio Member
 
Merlinb's Avatar
 
Join Date: May 2006
Location: Lancashire
The 126C has a rated secondary load of 10k, but you are loading it with a much higher resistance. If you want anything remotely like a hi-fi bandwidth, you're going to have to reduce the load resistance. But since the 126C is unity gain, it doesn't actually do anything useful in this circuit, so I would suggests forgetting about it and saving the iron for another project; a resistive load would give better performance.

The E180F is also going have some fairly taxing Miller capacitance (I guess about 250pF at least), which is rather a lot to load a cartridge with. Having said that, a lot of people seem to like the sound of a load of load capacitance, so this may be a moot point to you.

Last edited by Merlinb; 5th December 2014 at 08:33 AM.
  Reply With Quote
Old 5th December 2014, 09:58 AM   #6
diyAudio Member
 
Join Date: Nov 2009
Location: London, UK
As Merlinb says. Instead you could use E180F in pentode mode (stage 1) and avoid miller C issues at audio frequencies, BTW. You could also obtain more gain from stage 1 that way, perhaps enough to make stage 2 a true triode cathode follower (I haven't checked), and so get back the slight partition noise stage 1 penalty? And after all, E180F is a nice little pentode, seems rude not to use it that way IMO. Not clear what the tx's add, I'd agree save them for another project. HTH !
  Reply With Quote
Old 5th December 2014, 11:20 AM   #7
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally Posted by luckythedog View Post
As Merlinb says. Instead you could use E180F in pentode mode (stage 1) and avoid miller C issues at audio frequencies, BTW. You could also obtain more gain from stage 1 that way, perhaps enough to make stage 2 a true triode cathode follower (I haven't checked), and so get back the slight partition noise stage 1 penalty? And after all, E180F is a nice little pentode, seems rude not to use it that way IMO. Not clear what the tx's add, I'd agree save them for another project. HTH !
I got my inspiration here Hi-end phono preamplifier.
I also have some C3G, D3A, 6C4P, 6C3P, 6E6P. I plan to build some prototypes and compare them.
Thx for suggestions.
  Reply With Quote
Old 5th December 2014, 07:29 PM   #8
diyAudio Member
 
Join Date: Oct 2010
Location: se england
If you tie g2 and g3 to the plate with carbon resistors you can try out loads of pentodes without any changes d3a, 6j9 etc, some of them have opposite grid 2 and 3 pins. I have used dn2540 mu followers on my mc phonostage, you then take the aging anode impedance increase out of your filter calcs so frequently response should be more stable and at the output it works as your buffer
  Reply With Quote
Old 5th December 2014, 07:37 PM   #9
RajkoM is offline RajkoM  Bosnia and Herzegovina
diyAudio Member
 
Join Date: Feb 2009
Matej, do not skip this Damir RIAA preamp.

AudioRoundTable.com: Group Build => RIAA preamp project
  Reply With Quote
Old 6th December 2014, 05:21 AM   #10
seppoa is offline seppoa  Sweden
diyAudio Member
 
Join Date: Feb 2013
When talking about RIAA-stages, do you have any suggestion for how to use nuvistors type 7895/6CW4? I have built a phono preamp according to Hiraga, that sounds beautiful. But when talking to friends, someone said that nuvistors are tha sh... So very curious. Found some schematics, but want to ask, if you got experiences?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Better MC Pre-Pre solution for low internal coil resistance- not only for Pearl phono tiefbassuebertr Pass Labs 17 27th June 2014 10:54 AM
Phono pre share P/S with Main Pre? cogitech Analogue Source 5 5th April 2014 04:26 PM
How Can I connect A Balanced RIAA Phono Pre-Amp to a Phono Plug amp input jmartinbaugh Analogue Source 3 25th April 2011 02:24 PM
Pre-pre; phono; pre line ;device discrete (bjt/fet) o op. amplifier GIPIONE Solid State 8 18th December 2005 10:09 PM
Phono transformer VS Active phono pre ckwong99 Analogue Source 0 2nd November 2005 05:35 AM


New To Site? Need Help?

All times are GMT. The time now is 05:37 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2