It is currently Mon Mar 16, 2020 2:19 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 8 posts ] 
Author Message
Post subject: Bassman 5F6 Schematic????
Posted: Wed Oct 22, 2014 8:47 am
Offline
Hobbyist
Hobbyist

Joined: Thu Mar 04, 2010 4:52 am
Posts: 56
Location: Connecticut
Hi all, I came across this schematic and was wondering if anyone knows if it's accurate.
From all I've read on different forums, there are no accurate bassman 5F6 schematics.
That they all are missing changes made to the circuit as the amps were shipped.
Bob

Image


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Bassman 5F6 Schematic????
Posted: Wed Oct 22, 2014 10:25 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
There are so many 5F6 Bassman 's schematics we can found on the web . Are they same ?
That is your question ?
Or what do you want to know ?

Sometime Fender ( Leo ) made some change on the amps assembled line . Did schematic follow ?

There is 5F6 A too , not same


Top
Profile
Post subject: Re: Bassman 5F6 Schematic????
Posted: Wed Oct 22, 2014 12:41 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Mar 04, 2010 4:52 am
Posts: 56
Location: Connecticut
Sorry all,
I posted the schematic for the 5F6 and it should have been the 5F6-A.
They are almost identical.

Someone posted on another forum that he has a few 5F6-A amps that have not been modded and that they all have a 4.7K resistor connected from one end of the presence pot (the lug that connects the 27K feedback resistor) and then to ground.
I have a chance to pick up a empty chassis for a 5F6-A for a future project and I'm gathering info on it.
I'm just looking to see if anyone else has seen this resistor on one of these amps.
Thanks


Top
Profile
Post subject: Re: Bassman 5F6 Schematic????
Posted: Wed Oct 22, 2014 2:13 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
I have a lots of Bassman 6F6 -A schematics and all are the same . No 4.7 K

Did you know if this guy is qualified to know what he is talking about ?

Did you see some picture ? He may be right , but just one guy say that on a forum .... I read lots of false things on forum ........

You want to built this Bassman amp ?


Top
Profile
Post subject: Re: Bassman 5F6 Schematic????
Posted: Wed Oct 22, 2014 4:04 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Mar 04, 2010 4:52 am
Posts: 56
Location: Connecticut
stratele52 wrote:
I have a lots of Bassman 6F6 -A schematics and all are the same . No 4.7 K

Did you know if this guy is qualified to know what he is talking about ?

Did you see some picture ? He may be right , but just one guy say that on a forum .... I read lots of false things on forum ........

You want to built this Bassman amp ?


I wasn't aware that an electronics degree was required to look at a resistor and read the color code so I hesitate to call the person who wrote that post unqualified.
But that's only MHO.

But to satisfy your curiosity, here's a link to another post for a 5F6-A circuit with that resistor on a different forum. This one has pictures you can look at.

http://www.thegearpage.net/board/showthread.php?t=937179


Top
Profile
Post subject: Re: Bassman 5F6 Schematic????
Posted: Wed Oct 22, 2014 4:22 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Thank's for picture , you are right , this is a 4.7 K from pot lug to ground .

So the 5F6-A are not alway same !


Top
Profile
Post subject: Re: Bassman 5F6 Schematic????
Posted: Wed Oct 22, 2014 9:56 pm
Offline
Rock Star
Rock Star

Joined: Mon Apr 05, 2010 2:37 pm
Posts: 8708
Location: Natural Bridge, Virginia
The 4.7K resistor was added to the presence pot in late 59/early 60. Fender was/is not good at keeping their schematics up to date.

The purpose of the mod was to eliminate a "scratchy" sound when the pot is turned due to DC voltage on the pot in the original presence circuit design.

Image

Image

Because the presence pot circuit forms part of the "tail" in the long-tailed phase inverter circuit, the 10K resistor in the PI circuit is changed to 6.8K to maintain the same overall tail value for the PI.

_________________
Bill

Image


Top
Profile
Post subject: Re: Bassman 5F6 Schematic????
Posted: Thu Oct 23, 2014 2:04 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
This resistor was in the Bassman 6G6-B schematic .
A update of 6G6-A schematic ?


http://el34world.com/charts/Schematics/ ... _schem.pdf


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: