Best Valve pre-amp match for ME 550 amp - Page 4 - 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 8th December 2011, 02:47 AM   #31
diyAudio Member
 
Join Date: Mar 2006
Location: Australia
Quote:
Originally Posted by ChrisA View Post
"Add in parallel" was maybe confusing. I should have said "combine in parallel". The load on the output transformer will be one over the sum of the reciprocals.

I like using the load resistor because, As I said, "safety". It allows you to turn on the preamp with nothing plugged in

The other method is just to give up on building an all tube pre-amp and use a solid state output section
Is there a plan/schematic (or combination of them - like a plan) that you can point me to???, as I am new to this, and it would make much more sense from a workable practical perspective..., if possible/preferrable, some kind of 'triode' optimal low-zero noise configuration...
  Reply With Quote
Old 8th December 2011, 03:23 AM   #32
ChrisA is offline ChrisA  United States
diyAudio Member
 
Join Date: Jan 2008
Default What you need is a "headphone amp"

Quote:
Originally Posted by TigerScent View Post
Is there a plan/schematic (or combination of them - like a plan) that you can point me to???, as I am new to this, and it would make much more sense from a workable practical perspective..., if possible/preferrable, some kind of 'triode' optimal low-zero noise configuration...
Your requirements are almost unique. I doubt there is already something like this that some one could just link to. Not many power amps have such low input impedance. and few people would want to drive them with a tube based preamp.

My advice: Build something else as a first project. Perhaps a small tube power amp. But then you'd need speakers that can be driven with low power. Tube headphone amps are a good first project.

Oh. man, _slap forehead_, A headphone amp is very much like the thing you are looking for. I bet any of then would work.

Build a simple valve headphone amp and figure the first one is mostly for your own education, then build another. Along the way you will acquire skills and tools. Just start SIMPLE. and make the chassis over sized.


You can still decide on a transformer or not. I like them, others see then as big heavy $50 boxes. Google will turn up any number of headphone amp schematics

Last edited by ChrisA; 8th December 2011 at 03:27 AM.
  Reply With Quote
Old 8th December 2011, 03:39 AM   #33
diyAudio Member
 
Join Date: Mar 2006
Location: Australia
Quote:
Originally Posted by ChrisA View Post
Your requirements are almost unique. I doubt there is already something like this that some one could just link to. Not many power amps have such low input impedance. and few people would want to drive them with a tube based preamp.

My advice: Build something else as a first project. Perhaps a small tube power amp. But then you'd need speakers that can be driven with low power. Tube headphone amps are a good first project.

Oh. man, _slap forehead_, A headphone amp is very much like the thing you are looking for. I bet any of then would work.

Build a simple valve headphone amp and figure the first one is mostly for your own education, then build another. Along the way you will acquire skills and tools. Just start SIMPLE. and make the chassis over sized.


You can still decide on a transformer or not. I like them, others see then as big heavy $50 boxes. Google will turn up any number of headphone amp schematics
hmmm, it would be good to find one suitable (or close to-easily modified) first off.... might hunt around in this regard...
  Reply With Quote
Old 8th December 2011, 03:56 AM   #34
diyAudio Member
 
Join Date: Mar 2006
Location: Australia
Quote:
Originally Posted by ChrisA View Post
A headphone amp is very much like the thing you are looking for. I bet any of then would work.

Build a simple valve headphone amp and figure the first one is mostly for your own education, then build another. Along the way you will acquire skills and tools. Just start SIMPLE. and make the chassis over sized.
...what about a phono valve pre-amp?...or a combination of phono/headphone ideas for one?
  Reply With Quote
Old 8th December 2011, 05:19 AM   #35
diyAudio Member
 
Join Date: Mar 2006
Location: Australia
hmmmm, this looks interesting...I wonder what the output impedence would be???

TUBE RECTIFIED STEREO PRE-AMPLIFIER KIT
  Reply With Quote
Old 8th December 2011, 05:52 AM   #36
diyAudio Member
 
Join Date: Mar 2006
Location: Australia
then there is this one: http://www.pmillett.com/file_downloads/ax_lowmu.pdf
  Reply With Quote
Old 16th July 2012, 05:28 PM   #37
treuben is offline treuben  Australia
diyAudio Member
 
Join Date: Jul 2006
Default It's not all that special really..

The me-550 had a pretty usual input topography - the unusual low input impedance was set with a couple of resistors plugged into small sockets on the boards inside. Some people just cut or lifted a leg to give a more normal 50k unbalanced input that most things can drive. He used to have an info sheet he sent out regarding that.. Peter Stein's pre's were as powerful as little headphone amps (I used to drive my High impedance Sennheisers with them pretty happily.) but an all ME system, while about as dynamic as it gets, can be short on tubey warmth and depth of soundstage and plain listenability. A tube pre can be just the ticket to make low volume listening more satisfying and flesh out the acoustic guitar and vocals. I'm surprised Mr Stein didn't tell you though perhaps, like a lot of good engineers, he's better at answering the question you actually asked and not the one you *wanted* to ask. 8) I like ME stuff.. nicely made and great dynamics - very accurate, a lot like later Krell or Spectral. The 850 was pretty special with Apogees. A lot of them (all models) blew up for various reasons though.. they're not the simplest of animals and I guess that can be bad news for durability. Australia is also pretty harsh on high-bias power amps.. hell, it's not that habitable for humans a lot of the time!
  Reply With Quote
Old 7th January 2013, 11:54 PM   #38
diyAudio Member
 
Join Date: Mar 2006
Location: Australia
Quote:
Originally Posted by treuben View Post
The me-550 had a pretty usual input topography - the unusual low input impedance was set with a couple of resistors plugged into small sockets on the boards inside. Some people just cut or lifted a leg to give a more normal 50k unbalanced input that most things can drive. He used to have an info sheet he sent out regarding that.. Peter Stein's pre's were as powerful as little headphone amps (I used to drive my High impedance Sennheisers with them pretty happily.) but an all ME system, while about as dynamic as it gets, can be short on tubey warmth and depth of soundstage and plain listenability. A tube pre can be just the ticket to make low volume listening more satisfying and flesh out the acoustic guitar and vocals. I'm surprised Mr Stein didn't tell you though perhaps, like a lot of good engineers, he's better at answering the question you actually asked and not the one you *wanted* to ask. 8) I like ME stuff.. nicely made and great dynamics - very accurate, a lot like later Krell or Spectral. The 850 was pretty special with Apogees. A lot of them (all models) blew up for various reasons though.. they're not the simplest of animals and I guess that can be bad news for durability. Australia is also pretty harsh on high-bias power amps.. hell, it's not that habitable for humans a lot of the time!
Hey, thanks for that - that is what I figured. A tube-pre would be just the ticket.

Do you suggest I remove the resistors? Would sound quality be affected? (where are they lol )

Or just find a very low impedance (ie: 400ohm) tube pre, such as this one: 12AU7 Balance Tube Valve Preamplifier Amplifier DIY Kit ref AR (No Tube) | eBay
  Reply With Quote
Old 8th January 2013, 12:29 AM   #39
treuben is offline treuben  Australia
diyAudio Member
 
Join Date: Jul 2006
Sound quality is not affected though the unit may be more susceptible to hum and noise if you have very high efficiency speakers. See if you can't get rage audio or Peter Stein to send you a diagram. They ought to have them somewhere. Or you can post a high res picture and we can point them out.. I'm going to guess that they will be 820 or 620 ohm resistors in single leg socketed pins. (It was a while ago regarding the value but I'm almost certain they were between 620ohm and 1k)

Last edited by treuben; 8th January 2013 at 12:32 AM.
  Reply With Quote
Old 8th January 2013, 12:30 AM   #40
diyAudio Member
 
Join Date: Mar 2006
Location: Australia
This one looks like it could be a good one; not sure about the impedance tho: http://www.ebay.com.au/itm/JP-200-JP...item4ab888e981
  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
Best type of pre-amp for valve/tube power amp elgee Tubes / Valves 10 11th November 2011 10:40 AM
any advice on how to match a headphone level output to valve amp input levels? mondogenerator Headphone Systems 1 18th December 2009 03:08 AM
what guideline to match pre and amp? milen007 Tubes / Valves 5 2nd June 2008 05:58 AM
Valve Pre Amp & Class D Power Amp Puffin Tubes / Valves 7 16th June 2006 04:41 PM


New To Site? Need Help?

All times are GMT. The time now is 09:23 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