HRD > Bassman project! SUCCESS!!

Make it loud here.
Post Reply
User avatar
Dr Tony Balls
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 655
Joined: Thu Mar 12, 2015 10:05 am
Location: Brooklyn, NY
Contact:

Re: Another old friend... Now a HRD > Bassman project!

Post by Dr Tony Balls » Wed May 08, 2024 12:28 pm

JSett wrote:
Wed May 08, 2024 12:20 pm
I doubt you'll notice, but the turret board specified was 30x30. Turns out the layout requires 31x31
HA. The original board was 31!
Instagram: thetonyballs

User avatar
JSett
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 9626
Joined: Mon Jun 01, 2009 1:33 pm
Location: Old Hampshire, Old England

Re: Another old friend... Now a HRD > Bassman project!

Post by JSett » Wed May 08, 2024 12:36 pm

Dr Tony Balls wrote:
Wed May 08, 2024 12:28 pm
JSett wrote:
Wed May 08, 2024 12:20 pm
I doubt you'll notice, but the turret board specified was 30x30. Turns out the layout requires 31x31
HA. The original board was 31!
Was it? :D classic! I stared at the plans for a good 10-20 minutes trying to see if there was a way to gain a row but I sure as shit couldn't. Cut and paste to the rescue. If I was to do this more times, I'd make my own turret/eyelet boards.
Silly Rabbit, don't you know scooped mids are for kids?

User avatar
Scout
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 1025
Joined: Thu Feb 27, 2020 3:26 pm
Location: Phillyish

Re: Another old friend... Now a HRD > Bassman project!

Post by Scout » Wed May 08, 2024 1:20 pm

Almost all the parts are here now so I populated the board tonight. I find this extremely therapeutic...



It really is a nice diversion, isn't it.

User avatar
JSett
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 9626
Joined: Mon Jun 01, 2009 1:33 pm
Location: Old Hampshire, Old England

Re: Another old friend... Now a HRD > Bassman project!

Post by JSett » Mon May 13, 2024 9:54 pm

Massive update on this.

I went and got the donor amp back yesterday morning as I had the day off to tinker with this. Obviously, as always, I'm extremely industrious.

Ready to operate...

Image

The guts (I'll organ harvest that later :shifty: )...

Image

The cadaver...

Image

Thanks to MattK, I sourced these adaptors from eBay China for £10 shipped (for 4) instead of $60 from Angela...

Image

Used a lot of the existing chassis holes to mount/earth/etc things. I think, apart from the tube socket adaptors, I only had to drill 3 holes. That aside, I got the board in and stated running all the leads...

Image

A lovely bundle of redundant wires. BUT ARE THEY?!?

It turns out that export/import models have some weirdness going on which means the colours are NOT what you'd expect. In the end I had to connect BLK/GRN to BLK/YEL together and VIOLET and BLACK were the +/-. I blew a few fuses trying different combinations...

Image

There were a few more complications. Turns out the OT Primaries were backwards so they needed swapping. I also got 2 caps mixed up (0.01uF and 0.1uF in the tone circuit so the thing sounded awful. It took a bit of fucking about to fix that issue!!

Top panel is a mess for now, but it's functional...

Image

But it's all in, working, and seems to sound great! I can't test it at volume until tomorrow though...

Image

Image

Image

So, obviously MASSIVE thanks to Tony for inspiring and helping so much with this. This has been a much more educational effort that my last amp build - which was a little 'paint by numbers' really and wasn't a huge challenge. Not only did Tony help with the schematic and layout but he helped a ton last night with the problem solving required. Gratitude level 100.

Points of note: If I do another I will definitely make my own turret board and probably use vintage style wire for the flys. I like doing my electronics with all the nice clean angles bent in but a) I didn't have enough cloth-covered here in stock and b) seeing as it wasn't 'paint by numbers' I was more concerned with functionality.

So, several burns, a small fire, a jolt to the left hand (whoops), a tingly finger and a big old mess in the spare room later, I think its done!

Image
Silly Rabbit, don't you know scooped mids are for kids?

User avatar
sal paradise
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 4007
Joined: Thu May 27, 2021 12:41 am

Re: Another old friend... Now a HRD > Bassman project!

Post by sal paradise » Mon May 13, 2024 11:05 pm

That looks INCREDIBLE. Amazing work - can’t wait to hear demos! :w00t:

Are you pleased with it? I’m stoked for you :-*
I have nothing to offer anybody, except my own confusion?

User avatar
MattK
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 3858
Joined: Sun Aug 10, 2008 9:51 pm
Location: Hobart, Australia

Re: Another old friend... Now a HRD > Bassman project!

Post by MattK » Mon May 13, 2024 11:22 pm

Wowee! That looks awesome. Hope it sounds divine.

User avatar
OffYourFace
Mods
Mods
Posts: 14175
Joined: Thu May 03, 2007 2:59 pm
Location: Los Angeles, CA

Re: Another old friend... Now a HRD > Bassman project!

Post by OffYourFace » Tue May 14, 2024 12:36 am

sick

i just spotted THIS. I wish the cabinet was in better shape but it's an ideal price for a similar project.

User avatar
JSett
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 9626
Joined: Mon Jun 01, 2009 1:33 pm
Location: Old Hampshire, Old England

Re: Another old friend... Now a HRD > Bassman project!

Post by JSett » Tue May 14, 2024 4:15 am

Thanks everyone! Yeah, hopefully I can spend some time this evening/tomorrow with it and put it through its paces a little.

There's a couple of things I'd do differently if I was to do it again but otherwise, pending confirmation it possesses 'Le Rock', I'm a happy camper ;D
Silly Rabbit, don't you know scooped mids are for kids?

User avatar
Scout
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 1025
Joined: Thu Feb 27, 2020 3:26 pm
Location: Phillyish

Re: Another old friend... Now a HRD > Bassman project!

Post by Scout » Tue May 14, 2024 5:16 am

Well done! As far as right angle wiring goes, being an electrician there’s always a minimum radius required when bending conductors especially those subject to high temps. Granted it’s small in a 22 gauge but I like more of a neat sweep than a hard 90, just a thought.

User avatar
Dr Tony Balls
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 655
Joined: Thu Mar 12, 2015 10:05 am
Location: Brooklyn, NY
Contact:

Re: Another old friend... Now a HRD > Bassman project!

Post by Dr Tony Balls » Tue May 14, 2024 6:32 am

OffYourFace wrote:
Tue May 14, 2024 12:36 am
sick

i just spotted THIS. I wish the cabinet was in better shape but it's an ideal price for a similar project.
FUCK. These never show up this cheap in NYC.
Instagram: thetonyballs

User avatar
JSett
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 9626
Joined: Mon Jun 01, 2009 1:33 pm
Location: Old Hampshire, Old England

Re: Another old friend... Now a HRD > Bassman project!

Post by JSett » Tue May 14, 2024 6:36 am

Dr Tony Balls wrote:
Tue May 14, 2024 6:32 am
OffYourFace wrote:
Tue May 14, 2024 12:36 am
sick

i just spotted THIS. I wish the cabinet was in better shape but it's an ideal price for a similar project.
FUCK. These never show up this cheap in NYC.
Thats a great price. Here in the UK you can pick them up for £250-350 pretty much any day of the week.
Silly Rabbit, don't you know scooped mids are for kids?

User avatar
Dr Tony Balls
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 655
Joined: Thu Mar 12, 2015 10:05 am
Location: Brooklyn, NY
Contact:

Re: Another old friend... Now a HRD > Bassman project!

Post by Dr Tony Balls » Tue May 14, 2024 6:54 am

All I can find right now is a Pro Jr. for $250. I've done the same thing to one of those before, but its a little less utilitarian than the 30-40 1x12 guy.

What i'd really like to fuck with is one of those AC30CC things. Awhile ago i did some service on one and the guy took FOREVER to pick it up to the point where I was like "if its not picked up by this date, its mine". I was really hoping for that....was gonna gut it and make it a proper AC30.
Instagram: thetonyballs

User avatar
JSett
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 9626
Joined: Mon Jun 01, 2009 1:33 pm
Location: Old Hampshire, Old England

Re: Another old friend... Now a HRD > Bassman project!

Post by JSett » Tue May 14, 2024 12:57 pm

Okay. So there's a problem. The amp is EXTREMELY bassy. Even on 0 it's like it's on 7.

Now, I've gone over the circuit and connections a ton of times and I can't see anything wrong. All the values seem right, the pots seem wired correctly... But it's all bass and barely enough treble

Any help would be amazing....

Image
Image
Image
Image
Image
Image
Image
Silly Rabbit, don't you know scooped mids are for kids?

User avatar
JSett
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 9626
Joined: Mon Jun 01, 2009 1:33 pm
Location: Old Hampshire, Old England

Re: Another old friend... Now a HRD > Bassman project!

Post by JSett » Wed May 15, 2024 6:35 am

I definitely am stuck here.

After trying a million different things today and swapping parts etc there is nothing I can find that could be causing the bass-dominant tone of the thing. I lifted the mid resistor to bypass the entire tonestack and it was still there, so it's probably somewhere else.

So. I ripped the board out and remade the whole thing, checking every resistor with a multimeter out of circuit then back in. Redid all the rear jumpers too. It's now back to 'stock' as per the schematic and layout. Plugging my existing Ballsmom head into the cab & speaker proves it's the circuit that's the issue (as it sounded fine). The sheer amount of low frequency signal being let through somewhere is sapping all the power too and it's more like a 5w amp than 50w :D

It's a lot scruffier now I've had to redo the whole fucking thing :fp:

Image

Image

Image

Image

Image
Silly Rabbit, don't you know scooped mids are for kids?

User avatar
Dr Tony Balls
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 655
Joined: Thu Mar 12, 2015 10:05 am
Location: Brooklyn, NY
Contact:

Re: Another old friend... Now a HRD > Bassman project!

Post by Dr Tony Balls » Wed May 15, 2024 6:50 am

POST VOLTAGES!

Also what means do you have for checking bias? Bias probe or something?
Instagram: thetonyballs

Post Reply