YJM100 Power Scaling

Info for maintaining and tweaking your amp to perfection.

Moderator: VelvetGeorge

YJM100 Power Scaling

Postby dailey » Fri Feb 03, 2012 12:56 pm

Does anyone know if the whole amp is scaled or just the power tubes? I've done it both ways on a plexi 50w, sounds good either way to me if you don't slam the PI. I'm working on building a semi HW 50w version of the YJM100 with built-in booster, gate & digi reverb, tube driven series/ parallel loop & scaled. don't have a YJM100 to examine.
dailey
New Member
 
Posts: 12
Joined: Mon Dec 27, 2010 8:35 am

Re: YJM100 Power Scaling

Postby FortinAmps » Fri Feb 03, 2012 4:53 pm

dailey wrote:Does anyone know if the whole amp is scaled or just the power tubes? I've done it both ways on a plexi 50w, sounds good either way to me if you don't slam the PI. I'm working on building a semi HW 50w version of the YJM100 with built-in booster, gate & digi reverb, tube driven series/ parallel loop & scaled. don't have a YJM100 to examine.


It's just the screens with bias tracking. Same in the AFD.

Cheers,
Mike
User avatar
FortinAmps
New Member
 
Posts: 15
Joined: Mon Feb 01, 2010 3:03 pm
Location: Toronto, Canada

Re: YJM100 Power Scaling

Postby dailey » Tue Feb 07, 2012 12:23 pm

thanks for your help. I'll keep you posted on how it's going
dailey
New Member
 
Posts: 12
Joined: Mon Dec 27, 2010 8:35 am

Re: YJM100 Power Scaling

Postby dailey » Wed Feb 08, 2012 2:01 pm

Does anyone know if the 4th preamp tube is for the booster or just how it's used?
dailey
New Member
 
Posts: 12
Joined: Mon Dec 27, 2010 8:35 am

Re: YJM100 Power Scaling

Postby FortinAmps » Fri Feb 10, 2012 4:55 pm

dailey wrote:Does anyone know if the 4th preamp tube is for the booster or just how it's used?


The first preamp valve is 1/2 bright and 1/2 normal channel input, 2nd preamp valve is the 2nd stage mixer then CF into the tonestack, 3rd preamp valve is the fx loop return recovery and another cf, and the last preamp valve is the PI.

Cheers,
Mike
User avatar
FortinAmps
New Member
 
Posts: 15
Joined: Mon Feb 01, 2010 3:03 pm
Location: Toronto, Canada

Re: YJM100 Power Scaling

Postby dailey » Mon Feb 13, 2012 2:52 pm

thank you for your help, I'm working on the schematic & layout. looks like a wider than stock chassis is needed to keep everything under the hood. again, thank you.
dailey
New Member
 
Posts: 12
Joined: Mon Dec 27, 2010 8:35 am

Re: YJM100 Power Scaling

Postby FortinAmps » Tue Feb 14, 2012 2:11 pm

dailey wrote:thank you for your help, I'm working on the schematic & layout. looks like a wider than stock chassis is needed to keep everything under the hood. again, thank you.


No problem. The chassis is a bit larger than the normal 1959 style chassis.
http://www.tonymckenzie.com/yjm100_review.htm

Cheers,
Mike
User avatar
FortinAmps
New Member
 
Posts: 15
Joined: Mon Feb 01, 2010 3:03 pm
Location: Toronto, Canada


Return to Repairs, Restoration and Mods

Who is online

Users browsing this forum: neikeel and 1 guest