Go Back   Home > Forums > Amplifiers > Tubes / Valves
Home Forums Rules Articles Store Gallery Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

diyAudio Sponsor

Search for a tube at thetubestore.com                            Product reviews and more

Audio tubes for any amplifier: from high end home audio to classic guitar amps.

Quick links by tube type: 12AX7, EL34, 6L6, KT66, 6550, KT88, EL84, 12AU7, 12AT7, 6922, 6H30, 300B, 6V6, 6SN7 

Reply
 
Thread Tools Search this Thread
Old 15th July 2005, 07:27 AM   #1
diyAudio Member
 
Join Date: Nov 2002
Location: New York
Question diy guitar tube amp help.

Ok, somewhere, someone is going to read this any wonder why.....

About 3 years ago, I found a Hewlett Packard Audio Oscillator, Model 200B, a little rough.... but in working condition. I played around with it for a while and then put it on a shelf and forgot about it until tonight.

Lately, I've been reading about DIY tube amps and started thinking if it is possible to use some of the parts in the Oscillator to make a guitar tube amp?

I looked at the tubes in it...... 5V4G Rectifier Tube and Two 6K6GT tubes. I still don't see anything info wise on the Transformers, but then again...this was built in 1939 so I'm sure that dust from over the years is covering that up quite nicely.

I've done some searching on the internet but found sites that when you do the pricing for parts....well, I want to spend little as possible.

Is it possible to use some parts on this to make a guitar tube amp? Or should I just say forget it and try to sell it to someone that will actually use it and enjoy 30's Technology?

Any help for this learning DIY'er would be great!!!!!

Here is a pic of the cover off and looking down inside of it......
Attached Images
File Type: jpg top view.jpg (88.6 KB, 295 views)
  Reply With Quote
Old 15th July 2005, 07:31 AM   #2
diyAudio Member
 
Join Date: Nov 2002
Location: New York
Here are close ups on the left and right sides, along with eh front view.
Attached Images
File Type: jpg right.jpg (89.6 KB, 235 views)
  Reply With Quote
Old 15th July 2005, 07:33 AM   #3
diyAudio Member
 
Join Date: Nov 2002
Location: New York
Right side
Attached Images
File Type: jpg left.jpg (94.0 KB, 230 views)
  Reply With Quote
Old 15th July 2005, 07:39 AM   #4
diyAudio Member
 
Join Date: Nov 2002
Location: New York
Front View.
Attached Images
File Type: jpg front.jpg (80.8 KB, 241 views)
  Reply With Quote
Old 15th July 2005, 09:40 AM   #5
SHiFTY is offline SHiFTY  New Zealand
diyAudio Member
 
SHiFTY's Avatar
 
Join Date: Jul 2002
Location: New Zealand
If it goes, then you can use it.

I wouldn't turn it on for too long thouugh, the old components might go pop. Don't re-use any old capacitors or resistors, they might be a fire risk.

I would guess that if the oscillator has speaker outputs, then the transformer on the right is an output transformer, probably single ended. Otherwise you will need to buy one.

What you could do is completly strip that cool looking chassis down and build something like this Fender Princeton on it. Sub one 6K6 for a 6V6 and a 5V4 for a 5Y3, and all you need is a 12AX7.

http://www.kbapps.com/audio/schemati...ceton5f2a.html

If you can show the connectors and the underside of the unit, I can tell you more.

Also please read the safety thread
  Reply With Quote
Old 15th July 2005, 10:58 AM   #6
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Of course, some people would say that the HP200B is an important part of audio test equipment history and that you shouldn't destroy it...

I doubt if any of it is suitable for conversion. Many old oscillators did have a loudspeaker amplifier in them, but it would only be a Watt, or so.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 15th July 2005, 11:16 AM   #7
diyAudio Member
 
Join Date: Feb 2005
Location: texas
a 6K6 is just a slightly smaller 6V6. it looks like you might even have a P-P 6K6 output stage! see how they are wired to the output transformer. Also see if the thing can drive a speaker. If the output transformer can't drive a speaker there is no point is using this chassis. It looks like there are at least two small pentodes in there. use these for preamp and Phase inverter if needed.

First check to see if the HP200 is worth anything. If it is, resotore it and either hold on to it, use it (I find my function generator very useful for amp debugging), or sell it to buy more old tube junk!
  Reply With Quote
Old 15th July 2005, 11:39 AM   #8
diyAudio Member
 
Join Date: Jan 2005
IŽd clean this baby, change all small components and use it. Scrapping something like this is like killing someone.
  Reply With Quote
Old 15th July 2005, 11:43 AM   #9
diyAudio Member
 
Frank Berry's Avatar
 
Join Date: Sep 2003
Location: Midland, Michigan
If I remember correctly, this oscillator has a 600 ohm output.
__________________
Frank
  Reply With Quote
Old 15th July 2005, 11:53 AM   #10
diyAudio Member
 
Join Date: Feb 2005
Location: texas
if it's 600 ohm output, you should just clean it and replace the capacitors and use it. Especially if you don't already have a function generator. quite usefull things. I'd say the order you should get test equipment should be....

working brain, then a good multimeter, then a scope, and then a function generator. Once you get a scope and 'generator, you don't want to go back to the days where you only had a lowly multimeter....
  Reply With Quote

Reply


Hide this!Advertise here!

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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
Guitar tube pre DIY suggestions..? JandG Tubes / Valves 0 25th May 2007 11:18 PM
Now This is A Tube Guitar Amp!! Trout Tubes / Valves 9 14th August 2006 08:14 PM
Tube guitar amp sangram Instruments and Amps 6 2nd March 2003 04:54 PM


New To Site? Need Help?

All times are GMT. The time now is 02:19 AM.

Page generated in 0.10181 seconds (83.78% PHP - 16.22% MySQL) with 11 queries

Copyright ©1999-2012 diyAudio