Almost no output

Get support and show off your MetroAmp 50 Watt kit builds.

Moderator: VelvetGeorge

Post Reply
Lordhumongous
New Member
Posts: 1
Joined: Fri Feb 15, 2019 7:38 pm
Just the numbers in order: 13492

Almost no output

Post by Lordhumongous » Sun Mar 03, 2019 5:51 pm

Hello all! Just finished up my metro spec 1987. Sourced all the parts from valvestorm except a transformer set from classictone. Let me begin by saying I am NOT an amp tech. I just want to rock. I can follow directions however and sought to build one of my dream amps I couldn't otherwise afford. That being said, after start up, amp has almost no volume. Does emit a sad volume while turned all the way up. Eq and presence controls all function properly as well as bright channel is bright, normal channel is darker as one would expect. Does this sound familiar? Hoping someone can counsel me through this. Thank you :rockon:

stryker59
New Member
Posts: 1
Joined: Sun Apr 30, 2017 2:13 am
Just the numbers in order: 13492

Re: Almost no output

Post by stryker59 » Sun Mar 10, 2019 1:29 pm

Check the 470 ohm resistor between the 1m pair at the phase inverter and make sure you didn't use 470k ohm

User avatar
neikeel
Senior Member
Posts: 7231
Joined: Tue Dec 06, 2005 8:31 am
Location: Suffolk, England

Re: Almost no output

Post by neikeel » Tue Mar 12, 2019 8:14 am

Typical one is 470k cathode resistor on PI instead of 470R

Look and measure between the two 1M resistors on the board.
Neil

danman
Senior Member
Posts: 1099
Joined: Tue Sep 10, 2013 9:09 pm
Just the numbers in order: 13492

Re: Almost no output

Post by danman » Tue Mar 12, 2019 7:23 pm

Yep...Neikeel has the answer! Most likely a 470k between the two 1m resistors in the middle of the board instead of the correct 470 ohm. Happens quite a bit in new builds unless you measure every resistor before installing.

User avatar
neikeel
Senior Member
Posts: 7231
Joined: Tue Dec 06, 2005 8:31 am
Location: Suffolk, England

Re: Almost no output

Post by neikeel » Sun Mar 17, 2019 12:39 pm

:what:
Neil

danman
Senior Member
Posts: 1099
Joined: Tue Sep 10, 2013 9:09 pm
Just the numbers in order: 13492

Re: Almost no output

Post by danman » Sun Mar 17, 2019 6:48 pm

He must have got it sorted out and playing right :rock:

User avatar
axeman
Senior Member
Posts: 2464
Joined: Wed Apr 02, 2008 1:21 pm
Just the numbers in order: 7
Location: Los Angeles
Contact:

Re: Almost no output

Post by axeman » Mon Mar 18, 2019 12:55 am

He probably crossed the the green wire for V1? Not sure have to see.

Post Reply