Champ Micro build

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luau
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Champ Micro build

Post by luau » Wed May 04, 2022 11:37 am

The Champ Micro on Rob Robinette's site caught my eye and looks like fun. I've got to leave for FL this weekend and won't have time to work on it until I get back mid-May, but I cut the turret board material and staked the turrets on. Here's a picture with things arranged more or less where they'll go on the chassis.

Image.

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Re: Champ Micro build

Post by i love sharin foo » Wed May 04, 2022 3:21 pm

Awesome! That is a good start Tom! I'll be following along 8)
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Re: Champ Micro build

Post by Fiddy » Wed May 04, 2022 7:10 pm

Looking good. We'll stay tuned for updates.

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Re: Champ Micro build

Post by luau » Thu May 05, 2022 8:57 am

Well, I lied and spent some time on it last night. I either have a missing box from the move or didn't order all of what I think I did, because I don't have the other voltage dropping resistor. I'll jumper in a pot for the cathode bias resistor while I'm getting it going to decide on a value.

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Re: Champ Micro build

Post by JackFawkes » Thu May 05, 2022 9:07 am

It'll be fun to watch this develop.
The little bit that I think I've learned about amp circuits, I've learned from reading through Rob's website.

Jack

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Re: Champ Micro build

Post by jellodog » Thu Jun 02, 2022 4:58 am

Subscribed!

I've been obsessing over small amps and these Robinette micro builds recently - but haven't gone so far as starting a project. Really interesting in seeing and hearing how yours turns out.

Are you keeping track of component costs? I'd be interested in knowing rough costs and time spent when you're finished.

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Re: Champ Micro build

Post by marqueemoon » Thu Jun 02, 2022 9:36 am

Very interested in this! I don’t have the skills myself, but I just checked out a demo and it sounds great.

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Re: Champ Micro build

Post by Fiddy » Thu Jun 02, 2022 9:47 am

marqueemoon wrote:
Thu Jun 02, 2022 9:36 am
Very interested in this! I don’t have the skills myself, but I just checked out a demo and it sounds great.
You think you don't, but deep inside you do. Give one a try. Take your time. Go slow. Ask lots of questions.

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Re: Champ Micro build

Post by luau » Thu Jun 02, 2022 10:09 am

jellodog wrote:
Thu Jun 02, 2022 4:58 am
Subscribed!

I've been obsessing over small amps and these Robinette micro builds recently - but haven't gone so far as starting a project. Really interesting in seeing and hearing how yours turns out.

Are you keeping track of component costs? I'd be interested in knowing rough costs and time spent when you're finished.
Not counting tubes I think it'll be between 150 and 200. I guess I've got about 2 hours in it atm. The boards are populated and soldered up. I have a few joints to clean up and I'll get some pics up. Next up I think I'll probably build a simple jig and get the pots, jacks, and switches wired up on it. My enclosure is a blank so I need to drill it out and the jig will help with layout.

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Re: Champ Micro build

Post by luau » Thu Jun 02, 2022 10:17 am

marqueemoon wrote:
Thu Jun 02, 2022 9:36 am
Very interested in this! I don’t have the skills myself, but I just checked out a demo and it sounds great.
There was a lot of talk about bedroom amps some months back when I decided to try one of these and it was with a partial mind towards putting some together just as a service to the community and selling them for cost. Stay tuned.

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Re: Champ Micro build

Post by marqueemoon » Thu Jun 02, 2022 10:23 am

tribi9 wrote:
Thu Jun 02, 2022 9:47 am
marqueemoon wrote:
Thu Jun 02, 2022 9:36 am
Very interested in this! I don’t have the skills myself, but I just checked out a demo and it sounds great.
You think you don't, but deep inside you do. Give one a try. Take your time. Go slow. Ask lots of questions.
Part of me is tempted. My old colleague/friend (now retired) is very good tech, and maybe he could help.

Not a priority right now though. I still have a half finished guitar project and upgrades to my recording setup I want to make.

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Re: Champ Micro build

Post by marqueemoon » Thu Jun 02, 2022 10:47 am

luau wrote:
Thu Jun 02, 2022 10:17 am
marqueemoon wrote:
Thu Jun 02, 2022 9:36 am
Very interested in this! I don’t have the skills myself, but I just checked out a demo and it sounds great.
There was a lot of talk about bedroom amps some months back when I decided to try one of these and it was with a partial mind towards putting some together just as a service to the community and selling them for cost. Stay tuned.
Definitely. As mentioned before I have some other priorities for the near term but an extreme low watt amp has been on “the list” for a long time.

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Re: Champ Micro build

Post by Fiddy » Thu Jun 02, 2022 12:47 pm

marqueemoon wrote:
Thu Jun 02, 2022 10:23 am

Part of me is tempted. My old colleague/friend (now retired) is very good tech, and maybe he could help.

Not a priority right now though. I still have a half finished guitar project and upgrades to my recording setup I want to make.
All of us here can also help. Looking forward to you building one.

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Re: Champ Micro build

Post by luau » Sun Jun 12, 2022 4:28 am

I made some progress yesterday. I'll drill out the enclosure today and maybe get everything mounted.

Image

I've made a few mistakes along the way. These resistor leads are really delicate and I foolishly did the ground bus last rather than first so they've ended up a little mangled. I neglected to verify the operation of the switch so the boost switch that adds in the bypass cap may end up being a quiet switch that lifts it. The ground wire on the master volume's 3rd lug was to go up through the turret and not around it.

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Re: Champ Micro build

Post by hulakatt » Sun Jun 12, 2022 2:14 pm

Hey, you live, you fuck up, you fix it, you learn. That's the theory anyway. As long as you learn then you're good.
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