50w Hot Rod Plexi AFD #39

[purpletele]

What kind of meter? Try another meter. Cycling from OL to low mV is not a characteristic of an amp that is stable and sounds good unless you are Neil or Eddie.

My meter is a newer Klein, I'll try another meter and make a video. Thank you

Here is a quick video



Mod Edit: Fixed youtube link

[purpletele]

I would just reflow the solder joints for V6 and see if that helps.

Mark,

I'll try that and do the same to the components in line.

I would think I should be getting the same voltage as the other leg of the PI.

Cool amp, thanks for the puzzle

[M Fowler]

It's not a balanced PI so there will be some differences in voltage but not jumping around voltage.

[purpletele]

The Hot Rod 50 is complete with all of the features working correctly.

What a fun amp to play!!

Thanks Mark

[M Fowler]

Glad to here your loving it.

I was just at my local Guitar and amp show last Sunday and we rocked out all day. I'm the fat guy in green T on right side.

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[purpletele]

Glad to here your loving it.

I was just at my local Guitar and amp show last Sunday and we rocked out all day.

Mark,

How did the local respond to your wall of doom?

Are people requesting to buy those at the show?

[M Fowler]

Yes I had requests for stock JCM800 2204, JTM45 and several of the 50w Hot Rod Plexi's (HRP) and everyone said they loved that HRP.


For fun I also that my Ultimate High Gain Amp at the show with it's squealing high gain that scared a few of the players it has incredible high gain too much.

https://ampgarage.com/forum/viewtopic.php?f=9&t=31272

I need to address the lead dress around V1 to stop that oscillation at very high settings.

Mark

[maint_tech]

@Mark Fowler
Hey Mark I was going to start a HRP 50 build and have a couple questions if you wouldn't mind? In comparing the DBM sketch to your gutshots it looks like you dropped the 1000pF (C12) on the Mid pot wiper to gnd, the bass pot looks like it is connected as a variable resistor (2 legs) rather than a pot (3 legs), you added a resonance control and dropped the 100K (R37) from the Master Volume to go to the FX loop. Do I see that correctly? Can you comment on that and any other differences?
Thanks for your time.
Joe

[M Fowler]

I just saw this post and will respond soon.

[M Fowler]

@Mark Fowler
Hey Mark I was going to start a HRP 50 build and have a couple questions if you wouldn't mind? In comparing the DBM sketch to your gutshots it looks like you dropped the 1000pF (C12) on the Mid pot wiper to gnd, the bass pot looks like it is connected as a variable resistor (2 legs) rather than a pot (3 legs), you added a resonance control and dropped the 100K (R37) from the Master Volume to go to the FX loop. Do I see that correctly? Can you comment on that and any other differences?
Thanks for your time.
Joe

Yes the bass pot is wiper to first terminal (3).
I didn't see any need for the 100k prior to the PI coupling cap.
That mid pot 1000pf cap was Stephen's later addition, which I didn't use.

[maint_tech]

Thanks for the reply Mark.
One other thing, did you elevate the heaters on your builds?
I am collecting parts and making a full schematic, would it be Ok to post?
Joe

[M Fowler]

Joe,

I did not but would be a good idea or DC circuit at least on v1.

We run 5751 or 12au7 or 12ay7 in v1. Gain with 12ax7 is high.

Mark

[maint_tech]

I kinda thought elevation would be necessary with a cathode follower in the circuit...

[dorrisant]

Thanks for the reply Mark.
One other thing, did you elevate the heaters on your builds?
I am collecting parts and making a full schematic, would it be Ok to post?
Joe

Its fine to post... but you may want to start a new post.

[M Fowler]

A full schematic would be great.