First Tube Amp Considerations... - 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 2nd July 2004, 03:16 AM   #1
diyAudio Member
 
Frazzled's Avatar
 
Join Date: Apr 2004
Location: Regina, Saskatchewan
Default First Tube Amp Considerations...

OK...

Tonight I finished building an active crossover for my home sub-amp and I was sitting in my office with the lights out listening to some music when i found myself mesmerized by the soft incandescent glow of the meter lamps on my tuner and amp, I got to thinking that I would like and should finally build my first tube amp.

About 4 years ago I purchased a collection of 108 various tube amplification schematics, so I pulled out the collection and began to peruse the various circuits but being "NEW" to the whole tube scene (it's funny I should say "NEW" cause when I was a youngster even the car radios had tubes in them) I have no experience to help me decide what configuration I should try.

What I am looking for here is some advice as to sound quality, I am not necessarily looking for measurably accurate sound but rather that TUBE sound that everyone always talks so fondly of and some nice glowing tubes on the top of the chassis would be nice too!

So what is your recommendation; single ended, push pull would you say one particular output tube is better than another?
I am not looking to go simple for my first tube project cause odds are that I will only build one set of mono blocs and that will be that.

So come on folks help a fellow DIY'er out. I am really quite fond of the McIntosh MC40 or MC-275 chassis so building something similar in appearance to that would be cool too but then if I wanted McIntosh maybe I should just buy one right? but there is no fun in that.

Thanks one and all for your time and consideration.
__________________
Anything worth trying is worth failing at once or twice.
  Reply With Quote
Old 2nd July 2004, 04:39 AM   #2
SHiFTY is offline SHiFTY  New Zealand
diyAudio Member
 
SHiFTY's Avatar
 
Join Date: Jul 2002
Location: New Zealand
My 2c:

Quote:
I am not necessarily looking for measurably accurate sound but rather that TUBE sound that everyone always talks so fondly of and some nice glowing tubes on the top of the chassis would be nice too!
You might be surprised: a well designed tube amp will sound pretty accurate.

I would suggest the venerable williamson design, 6L6G or 807 push-pull with a long tailed pair 6SN7 or 12AU7 driver, perhaps a pentode front end like 6J7 or EF86? Vintage tubes are great when you can get them, dont worry about them being 40 years old! Power out would be 20-30W. Use vintage output transformers if you can get them.

I have found that a well designed PP amp comes close to a SET amp in sound quality, with the advantage of a decent amount of power.

Quote:
odds are that I will only build one set of mono blocs and that will be that.
Heard that before
  Reply With Quote
Old 2nd July 2004, 08:03 AM   #3
diyAudio Member
 
Frazzled's Avatar
 
Join Date: Apr 2004
Location: Regina, Saskatchewan
Quote:
Originally posted by ShiFtY
My 2c:



You might be surprised: a well designed tube amp will sound pretty accurate.

I would suggest the venerable williamson design, 6L6G or 807 push-pull with a long tailed pair 6SN7 or 12AU7 driver, perhaps a pentode front end like 6J7 or EF86? Vintage tubes are great when you can get them, dont worry about them being 40 years old! Power out would be 20-30W. Use vintage output transformers if you can get them.

I have found that a well designed PP amp comes close to a SET amp in sound quality, with the advantage of a decent amount of power.


How about something like this
Click the image to open in full size.



Quote:
Heard that before
I'll bet
__________________
Anything worth trying is worth failing at once or twice.
  Reply With Quote
Old 2nd July 2004, 08:46 AM   #4
diyAudio Member
 
Join Date: Apr 2004
Location: Monroe Township, NJ
Frazzled,

Where did the schematic come from? The 6L6s are triode wired. I question the ability of 12AX7 sections to drive the Miller capacitance of the "finals".

For sure, I'd change the 1 MOhm grid leak resistor at the circuit's I/P to 100 KOhms.
__________________
Eli D.
  Reply With Quote
Old 2nd July 2004, 09:51 AM   #5
MIKET is offline MIKET  United States
diyAudio Member
 
MIKET's Avatar
 
Join Date: Jul 2003
Location: Maine
Send a message via Yahoo to MIKET
Default 8SL7-6SN7-6L6

I think this may be what you are looking for:
http://www.dc-daylight.ltd.uk/Valve-...26K%20Fig3.pdf
  Reply With Quote
Old 2nd July 2004, 03:41 PM   #6
diyAudio Member
 
Frazzled's Avatar
 
Join Date: Apr 2004
Location: Regina, Saskatchewan
Default Re: 8SL7-6SN7-6L6

Quote:
Originally posted by MIKET
I think this may be what you are looking for:
http://www.dc-daylight.ltd.uk/Valve-...26K%20Fig3.pdf

Hmmmm Interesting, this circuit is very similar to the one I posted, I guess tube amps are like SS amps in that there are some standardized circuit configurations that designers use to put their own parts into to obtain their own preferred sound.

Can anyone else chime in as to their favorite design, my speaker sensitivity is in the mid 90's and my budget could be just about anything, the more $$ I need to spend, the longer I will take to finish the project, I get more out of the process than the actual finished project cause it is more about filling my free time and learning more about my chosen hobby, really the only time I listen to music is when I am in my office working on a new audio project.

Thanks again everyone.
__________________
Anything worth trying is worth failing at once or twice.
  Reply With Quote
Old 2nd July 2004, 03:48 PM   #7
diyAudio Member
 
Frazzled's Avatar
 
Join Date: Apr 2004
Location: Regina, Saskatchewan
Exclamation Esthetic

Remember guys, as well as decent sound there is an esthetic I am going for here, I see some of the photos of tube amps that are posted here and some leave me wanting while others bring a big smile to my face, big glowing tubes just turn me on, kinda takes me back to my childhood sitting in front of my grandfathers console radio/record player, listening to his 78's, I used to love that bassy silky smooth sound, the first CD I ever played repulsed me, way too "tinny" ya know.
__________________
Anything worth trying is worth failing at once or twice.
  Reply With Quote
Old 2nd July 2004, 04:20 PM   #8
diyAudio Member
 
Join Date: Apr 2004
Location: Monroe Township, NJ
Frazzled,

If your mid 90s SPL speakers have reasonably flat impedance curves, they are good candidates to be mated with single ended 300B based amplification of about 8 WPC O/P. You would get the tube sound "in spades". 300Bs are big coke bottle shaped tubes that will provide eye and ear candy.
__________________
Eli D.
  Reply With Quote
Old 2nd July 2004, 04:50 PM   #9
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Stick to well-proved designs for your first go. You'll end up with something that works well and can last you a long, long time. Or at the least, a nice platform from which you can start experimenting. Shifty mentions Williamson, which is a very sound idea (ouch). I'd also recommend the Mullard 5-20.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 2nd July 2004, 04:50 PM   #10
diyAudio Member
 
Frazzled's Avatar
 
Join Date: Apr 2004
Location: Regina, Saskatchewan
Quote:
Originally posted by Eli Duttman
Frazzled,

If your mid 90s SPL speakers have reasonably flat impedance curves, they are good candidates to be mated with single ended 300B based amplification of about 8 WPC O/P. You would get the tube sound "in spades". 300Bs are big coke bottle shaped tubes that will provide eye and ear candy.

Sweet, how about something like this...

Click the image to open in full size.
__________________
Anything worth trying is worth failing at once or twice.
  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
Pre-amp considerations. jerryo Solid State 41 29th May 2008 05:03 PM
X amp considerations DiMenSioN Pass Labs 26 30th May 2007 10:21 PM
P3A considerations sobazz Solid State 52 3rd January 2004 01:19 PM


New To Site? Need Help?

All times are GMT. The time now is 02:24 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