The Steel Guitar Forum Store 

Post new topic Model 6A Goodrich Matchbox problems
Reply to topic
Author Topic:  Model 6A Goodrich Matchbox problems
Virgil Franklin


From:
Indiana, USA
Post  Posted 18 Jun 2024 9:27 am    
Reply with quote

Model 6A Goodrich Matchbox problems:

No volume/ gain until 8 and then just distortion..

any ideas?
_________________
Virgil Franklin
Organizer: Southern Indiana Steel Guitar Show www.southernindianasteelguitar.com
2023 Justice Pro-lite 4 x 4,2020 Justice Pro-Lite 4 x 4 , S10 1977 Dekley 3x3, Stringmaster Mk1 Clone, Gibson Console Grande 520, Boss Katana 100 Mk2 with Basslite 2012 speaker
View user's profile Send private message Send e-mail Visit poster's website

Tucker Jackson

 

From:
Portland, Oregon, USA
Post  Posted 18 Jun 2024 9:26 pm    
Reply with quote

Hi, Virgil.

Maybe it needs a fresh battery?

It's always a good idea to try out some different cables too.
View user's profile Send private message Send e-mail

Virgil Franklin


From:
Indiana, USA
Post  Posted 19 Jun 2024 2:52 am    
Reply with quote

Absolutely...
Change of batteries... cables..then ..changed out gain pot..
_________________
Virgil Franklin
Organizer: Southern Indiana Steel Guitar Show www.southernindianasteelguitar.com
2023 Justice Pro-lite 4 x 4,2020 Justice Pro-Lite 4 x 4 , S10 1977 Dekley 3x3, Stringmaster Mk1 Clone, Gibson Console Grande 520, Boss Katana 100 Mk2 with Basslite 2012 speaker
View user's profile Send private message Send e-mail Visit poster's website

Mike Auman


From:
North Texas, USA
Post  Posted 19 Jun 2024 7:28 am    
Reply with quote

Virgil, if you've changed the gain pot, then the likely culprit is the op amp, I've seen one fail in a 6A. If it looks similar to this, the part number is Motorola MC33171, hopefully Goodrich mounted it in a socket like here, so you can just pop it out rather than desoldering.


Here's a source for the op amp: https://www.mouser.com/ProductDetail/511-MC33171DT

This replacement is a surface mount part (suffix DT), they don't make the original DIP thru-hole version any longer (suffix P), so you'll need an adapter like this, it matches the new part to the old circuit board: https://www.mouser.com/ProductDetail/910-PA0001 .

All you need is about $15 for parts and shipping from Mouser, and a steady hand for soldering small leads. Here's what the fix looks like on a newer 6A, with the replacement op amp and adapter board:



_________________
Long-time guitar player, now wrestling with lap steel.
View user's profile Send private message Send e-mail

Virgil Franklin


From:
Indiana, USA
Post  Posted 19 Jun 2024 9:05 am    
Reply with quote

Thank you so much.Appreciate greatly, but unfortunately, this one looks like it's pre Op amp IC and uses three transistors so i'm back to checking the transistors to see if one of them is not happy..
_________________
Virgil Franklin
Organizer: Southern Indiana Steel Guitar Show www.southernindianasteelguitar.com
2023 Justice Pro-lite 4 x 4,2020 Justice Pro-Lite 4 x 4 , S10 1977 Dekley 3x3, Stringmaster Mk1 Clone, Gibson Console Grande 520, Boss Katana 100 Mk2 with Basslite 2012 speaker
View user's profile Send private message Send e-mail Visit poster's website

Mike Auman


From:
North Texas, USA
Post  Posted 19 Jun 2024 10:57 am    
Reply with quote

Agreed, I would just change them one at a time.
_________________
Long-time guitar player, now wrestling with lap steel.
View user's profile Send private message Send e-mail

Virgil Franklin


From:
Indiana, USA
Post  Posted 23 Jun 2024 6:43 pm    
Reply with quote

They are a very common transistor.. availble for pennies a piece...
MPSA18
_________________
Virgil Franklin
Organizer: Southern Indiana Steel Guitar Show www.southernindianasteelguitar.com
2023 Justice Pro-lite 4 x 4,2020 Justice Pro-Lite 4 x 4 , S10 1977 Dekley 3x3, Stringmaster Mk1 Clone, Gibson Console Grande 520, Boss Katana 100 Mk2 with Basslite 2012 speaker
View user's profile Send private message Send e-mail Visit poster's website


All times are GMT - 8 Hours
Jump to:  

Our Online Catalog
Strings, CDs, instruction,
steel guitars & accessories

www.SteelGuitarShopper.com

Please review our Forum Rules and Policies

Steel Guitar Forum LLC
PO Box 237
Mount Horeb, WI 53572 USA


Click Here to Send a Donation

Email admin@steelguitarforum.com for technical support.


BIAB Styles
Ray Price Shuffles for
Band-in-a-Box

by Jim Baron
HTTP