Modifing A Fender Bassman Scheme

amirmk · 16th September 2005, 05:41 PM

Hello, I want to build a bassman but i don't need the bass preamp, what parts of it should i change after i erase the bass pre and coupling resistors?
scheme can be found here

gl · 16th September 2005, 05:45 PM

Hi amirmk,

Remaove all of the bass pre-amp parts up to and including the 470K resistor. I have built many of Fenders circuits and they are easy to modify like this. You will probably have no problems and be pleased with the result.

Cheers,
Graeme

amirmk · 16th September 2005, 06:12 PM

I want to do two other modifications, one is to remove everything but the basic preamp and poweramp of a Vox AC30, and the second one is to replace the valves in the bassman to 6550, is the first one done the same way?

gl · 16th September 2005, 06:43 PM

Hi amirmk,

I have never worked with the AC30 circuits so I can't offer any advice there. However, there is a great deal of info on the web on the AC30 so I would recommend a thorough search as a starting point. Perhaps other members here have some experience and could comment.

As for substituting the 6550, I don't see the point. The 5881 is a 6L6. The 6L6 and 6550 will sound very similar. If you want to use the 6550 to gain more power then I would advise finding a 6550 based circuit to build.

I like this vintage of Fender pre-amp very much and I own an original 6G7 Bandmaster. I consider this pre-amp circuit (the normal channel) to be the best one Leo ever did. Please note the tapped volume control. These are available in the US the last I checked but you may have trouble locating one in your area.

Graeme

gl · 16th September 2005, 06:45 PM

To the moderators.

Perhaps this thread belongs in musical instruments.

Cheers,
Graeme

amirmk · 16th September 2005, 07:34 PM

Thank you very much.
I don't know if it belongs in the instruments forum, as there are several guitar threads in this forum. Anyway, it doesn't matter to me. Next time i'll write it there.
Thanks again.

16th September 2005, 05:41 PM	#1
amirmk diyAudio Member Join Date: Nov 2004 Location: Israel	Modifing A Fender Bassman Scheme Hello, I want to build a bassman but i don't need the bass preamp, what parts of it should i change after i erase the bass pre and coupling resistors? scheme can be found here

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Fender Bassman Ten	Benny Bennett	Instruments and Amps	2	2nd April 2009 01:01 PM
My 66 Fender bassman tube guitar amp is cutting out intermittently and is making a bl	signalpaths	Tubes / Valves	6	8th June 2008 04:21 PM
antique fender bassman 50 retubed HELP	firefart_1st	Tubes / Valves	1	26th May 2008 11:06 PM
Fender Bassman- AB165 capacitor toss up	Willampsburn	Tubes / Valves	1	9th February 2008 02:12 AM
Fender Bassman PT Rewind	OKBill	Tubes / Valves	4	14th January 2007 02:51 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

16th September 2005, 05:45 PM	#2
gl diyAudio Member Join Date: Dec 2003 Location: Sierra Foothills - California	Hi amirmk, Remaove all of the bass pre-amp parts up to and including the 470K resistor. I have built many of Fenders circuits and they are easy to modify like this. You will probably have no problems and be pleased with the result. Cheers, Graeme

16th September 2005, 06:12 PM	#3
amirmk diyAudio Member Join Date: Nov 2004 Location: Israel	I want to do two other modifications, one is to remove everything but the basic preamp and poweramp of a Vox AC30, and the second one is to replace the valves in the bassman to 6550, is the first one done the same way?

16th September 2005, 06:43 PM	#4
gl diyAudio Member Join Date: Dec 2003 Location: Sierra Foothills - California	Hi amirmk, I have never worked with the AC30 circuits so I can't offer any advice there. However, there is a great deal of info on the web on the AC30 so I would recommend a thorough search as a starting point. Perhaps other members here have some experience and could comment. As for substituting the 6550, I don't see the point. The 5881 is a 6L6. The 6L6 and 6550 will sound very similar. If you want to use the 6550 to gain more power then I would advise finding a 6550 based circuit to build. I like this vintage of Fender pre-amp very much and I own an original 6G7 Bandmaster. I consider this pre-amp circuit (the normal channel) to be the best one Leo ever did. Please note the tapped volume control. These are available in the US the last I checked but you may have trouble locating one in your area. Graeme

16th September 2005, 06:45 PM	#5
gl diyAudio Member Join Date: Dec 2003 Location: Sierra Foothills - California	To the moderators. Perhaps this thread belongs in musical instruments. Cheers, Graeme

16th September 2005, 07:34 PM	#6
amirmk diyAudio Member Join Date: Nov 2004 Location: Israel	Thank you very much. I don't know if it belongs in the instruments forum, as there are several guitar threads in this forum. Anyway, it doesn't matter to me. Next time i'll write it there. Thanks again.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)