Mono Class A SE Schematics - 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 June 2007, 04:21 PM   #1
diyAudio Member
 
Join Date: Jun 2007
Default Mono Class A SE Schematics

I was wondering if somebody would point me in the direction of schematics for great sounding mono block SE amps? Schematics for a pre-amp would be groovy too.

I donít need it to be stupid loud but Iím going to be driving a pair of Martin Logan electro-statics. Iím not afraid of building something that is difficult. I plan on doing the layout myself and designing the enclosure. My budget is around $1k, but cheaper is better.

I recently left my job where I built R&D prototypes and took a job where Iím reviewing requirements and overseeing projects. I miss being in the shop. Iíve always wanted to build a tube amp but I donít know much about designing one (we spent maybe 10 minutes talking about tubes in my EE transistor class).
  Reply With Quote
Old 9th June 2007, 12:14 AM   #2
Nanook is offline Nanook  Canada
diyAudio Member
 
Nanook's Avatar
 
Join Date: Feb 2004
Location: Chinook Country.Alberta
Default so many schematics out there.

I've been looking into various schematics lately. Do a search here at diyaudio.com. Also do some searches for Peter Millet, Gary Pimm, etc. Or do a "classic" design.

Is your budget for the amps and preamp? Do you need a phono stage in there as well?
__________________
stew -"A sane man in an insane world appears insane."
  Reply With Quote
Old 9th June 2007, 12:21 AM   #3
diyAudio Member
 
Join Date: Apr 2004
Location: Monroe Township, NJ
ML hybrid 'stats are VERY power hungry. To drive them with a SE tube amp is going to need a transmitting type whose multi KV B+ requirements are DEADLY dangerous. That's not a good choice for a 1st project.

IMO, you should do the preamp 1st and get some experience under your belt. You have a fighting chance to survive a mistake at a couple of hundred Volts.

I've attached a schematic for a simple 12B4 based line stage. A few tweaks to that circuit and you have a low gain, low O/P impedance unit that can drive the nasty IHF "standard" of 10 KOhms. Use the SS power amplification you already own.
Attached Images
File Type: gif 12b4pre.gif (3.0 KB, 707 views)
__________________
Eli D.
  Reply With Quote
Old 9th June 2007, 12:27 AM   #4
jarthel is offline jarthel  Australia
diyAudio Member
 
Join Date: Jan 2002
Location: somewhere in Australia
Default Re: so many schematics out there.

Quote:
Originally posted by evancich
I was wondering if somebody would point me in the direction of schematics for great sounding mono block SE amps?
one thing to note is that any design can be monoblock. it only means you have separate chassis and separate power supplies. So any circuit you see out there can be made into a monoblock.

Another thing to note with monoblocks is the cost. As mentioned above, you have 2 chassis and 2 power supplies and other (like binding post, rca jacks and etc) instead of one. So, you might have to rethink your budget.
  Reply With Quote
Old 9th June 2007, 01:32 AM   #5
Nanook is offline Nanook  Canada
diyAudio Member
 
Nanook's Avatar
 
Join Date: Feb 2004
Location: Chinook Country.Alberta
Default evancich... Martin Logans...

oops, didn't read into that.

an arc welder is usually needed to drive em. They are power hungry for sure.. Besides the lack of efficiency, they need current.

Although they can sound wonderfull.

If tubes required then big power AB tubes would be the way to go for the top, assuming you have an active sub-woofer built into them. for the bottom
__________________
stew -"A sane man in an insane world appears insane."
  Reply With Quote
Old 9th June 2007, 05:45 PM   #6
diyAudio Member
 
Join Date: Jun 2007
Thanks for the tips.

Yep, my budget is everything: amps, psu, pre-amp.

I don't need a phono stage.

I feel pretty comfortable around high-voltage. I used to build MassSpec's that used 40kV. I spent time on Navy ships messing around with old radio and radar tubes.

I've friendly with a machine shop in my area and they will make the fab the enclosure for cost.

I always wanted seperates. When I was a kid reading stereophile, I dreamed about krell monoblocks and wilson speakers. That is totally out of my budget, but if I can build some tube monoblocks...
  Reply With Quote
Old 9th June 2007, 06:20 PM   #7
diyAudio Member
 
Join Date: Apr 2004
Location: Monroe Township, NJ
Forget about SE. O/P trafo costs alone will bust the budget.

Build a preamp 1st. That will get get your feet wet and position you for the monoblock project. The 12B4 circuit I previously posted has some gain. That gain would allow you to use the 12AT7 splitter/driver found in "El Cheapo" in front of PP KT88s. 60 honest WPC should provide decent listening levels in combination with your M/L speakers.

BTW, a set of Dyna MK3 reproduction trafos from Triode Electronics will cost about $250 per monoblock.
__________________
Eli D.
  Reply With Quote
Old 10th June 2007, 03:34 AM   #8
diyAudio Member
 
Join Date: Jun 2004
Location: Wylie, Texas
I second the suggestion on push-pull KT88's... that's what I would build!

All in favor?.....
  Reply With Quote
Old 11th June 2007, 05:41 AM   #9
diyAudio Member
 
Miles Prower's Avatar
 
Join Date: May 2005
Location: USA
Blog Entries: 6
Default Re: Mono Class A SE Schematics

Quote:
Originally posted by evancich
I was wondering if somebody would point me in the direction of schematics for great sounding mono block SE amps? Schematics for a pre-amp would be groovy too.

I donít need it to be stupid loud but Iím going to be driving a pair of Martin Logan electro-statics.
Single-enders won't work with those speeks. Most of your class A1 SE amps don't put out much more than five watts (and a great many not even that) and are used with high efficiency speeks with enough sensitivity to produce listenable volumes with very little power, sometimes under one watt.

Another big problem is SE OPTs. The more current they need to support, the more difficult to wind a really good one that can stand the DC core magnetization, maintain primary Xl at the low end, and have minimal stray capacitance and leakage inductance for good high end operation all at the same time. Unless you're gonna change the speeks, go with a PP amp.

Quote:
Iíve always wanted to build a tube amp but I donít know much about designing one (we spent maybe 10 minutes talking about tubes in my EE transistor class).
Most of what you learned in transistor class is transferable. Go Here, look in the "Downloads" section for "RDH4" and download that. It's well worth while to spend some time studying that before beginning anything.
__________________
There are no foxes in atheistholes
www.dolphin-hsl.com
  Reply With Quote
Old 11th June 2007, 07:02 AM   #10
Klimon is offline Klimon  Belgium
diyAudio Member
 
Join Date: Apr 2005
Location: Leuven
Quote:
All in favor?
...okay then!

Or parallel PP as a less attractive alternative.

Simon
  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
Class-T amp with subwoofer - impedance? mono or stereo? pdvrog Subwoofers 6 14th July 2008 06:04 PM
Recommend a 2W, Class D mono for guitar jackinnj Instruments and Amps 13 24th December 2007 01:18 PM
MTX Thunder 3401 Class D Mono Amp gssmind Swap Meet 11 6th October 2006 11:32 AM
Battery powered portable Class-D mono amp >50W RMS tonfelix Class D 1 29th April 2006 03:08 PM
I need some low powered MONO FM transmitter schematics..!! xitronics Everything Else 0 30th May 2005 06:14 AM


New To Site? Need Help?

All times are GMT. The time now is 05:57 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