Welcome to Solid State Guitar Amp Forum | DIY Guitar Amplifiers. Please login or sign up.

November 14, 2025, 08:37:47 AM

Login with username, password and session length

Recent Posts

 

Realistic MPA-100

Started by saturated, October 26, 2025, 09:49:38 PM

Previous topic - Next topic

g1

The cap has the 4 as a multiplier, not as a digit.  So 33 with 4 zeroes, in pF.
For the transistor sub, power and current & Hfe look ok but I don't think the Vceo of the TTC015B is sufficient.  I would look for the TTC004B.

saturated

Yes sir thanks also I think I learned 1H means 50 v DC  xP
I ask stupid questions
and make stupid mistakes

criticism, critique, derision, flaming, verbal abuse welcome

saturated

Ok
Got my transistors in yesterday so today didn't have a lot of time but hey onward we go

Anyhow wife gave me too much coffee so I had some hella jitters trying to get this in

Also I verified pinout etc

You cannot view this attachment.

And the ugly truth

Oh yeah that nut that was glued to the board and fell off added to the entertainment

You cannot view this attachment.

I did not have tons of confidence in this install so I checked for continuity but fingers crossed apparently no solder bridges

So now just waiting on my capaci-TATERS  :'(  :'(

I ask stupid questions
and make stupid mistakes

criticism, critique, derision, flaming, verbal abuse welcome

saturated

#18
Too much fun

Just had a cow looking at the collector which appears to be touching the heatsink  :grr

Anyhow I did some more continuity tests and I think it's ok but yeah gonna have to pay attention to stuff like that

You cannot view this attachment.


EDIT:  note to self.  Next time you need to bend the legs 90 degrees approximate the horizontal distance needed then find a nice firm sharp 90 degree edge to use as a die
Because it also messes up trying to solder when legs are coming through the hole at an angle SMH

EDIT 2: Maybe instead of nice sharp 90 degree edge I should have said nice CRISP edge.  Like when I used to be in Alberta and when I got cold ❄️🥶 the locals would say "She's getting CRISP" 
I ask stupid questions
and make stupid mistakes

criticism, critique, derision, flaming, verbal abuse welcome

Jazz P Bass

That 'heatsink' looks to me to be a ceramic pad (for heatsinking purposes).
It should be nonconductive.

saturated

Well I got my capaci-TATERS in

You cannot view this attachment.

Got home from work and installed

You cannot view this attachment.

Clipped the leads

You cannot view this attachment.

Reattached the board which was a major pita getting that little spade fork under the ground screw

Powered it up and its about the same it doesn't get loud with both volumes maxed.

You cannot view this attachment.

Im declaring a marginal "success" because I've had it on for a while and it's not shutting off like it was before.

Also I noticed that the bottom chassis is not getting warm 🥵 anymore.

I just felt the little "heatsink" and it's pretty warm but not hot.

So kinda inconclusive since I wouldn't even know how to operate this amp if it was brand new.  Might be time to get a 🎤 microphone 🎙�

When I first powered it up to test it I got no sound but forgot about this already molested wire wrap so I attached it and had the same low sound.

You cannot view this attachment.

There are two posts maybe I should try the other one but I don't want to short something out.   :grr

Or maybe I need to study the schematic kindly provided and try to figure it out. 

Or maybe they both need to be connected to a wire  :grr  :'(

 xP

I ask stupid questions
and make stupid mistakes

criticism, critique, derision, flaming, verbal abuse welcome

saturated

Ok nm yes it does get pretty loud I had the knobs facing away from me I thought the two on the end were aux/phono volume and master volume.

Turns out the tone knob is on the end so when I turned aux/phono it started to get loud.  :tu:
I ask stupid questions
and make stupid mistakes

criticism, critique, derision, flaming, verbal abuse welcome