Harmony H307X project
- Tumtrah
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- Location: Hamburg area, Germany
Harmony H307X project
Traded this Harmony amp in for an accutronics reverb tank. It has a broken cabinet, changed/modified circuit, non original OPT, knobs and speaker.
- jthomas
- PAT. # 2.972.923
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- Location: Downeast Maine
Re: Harmony H307X project
Looks like a fun resto project.
- Tumtrah
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- Location: Hamburg area, Germany
Re: Harmony H307X project
It's a lightweight amp due to the cabinet which is build out of soft fiber/soft board (don't know how it's called in English). At first I thought I would build a new one, but i can do that later and try to fix it.
- Fiddy
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Re: Harmony H307X project
Its called particle board.
Good stuff. You should do up a new cabinet though. Particle board sucks.
- Tumtrah
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- Location: Hamburg area, Germany
Re: Harmony H307X project
Thanks for the definition! Due to the porous material I tried polyurethane glue to fix the cabinet and it seems to work.
Maybe particle board sounds good? Nevertheless this will not be my amp for gigging.
I did some research and found two usefull links to reconstruct the circuit:
https://oldamps.weebly.com/harmony-h307x.html
https://lectrolab.wordpress.com/lectrolab-models/r600/
The Lectrolab R600C is circuitry-wise identical to the Harmony H307X.
Maybe particle board sounds good? Nevertheless this will not be my amp for gigging.
I did some research and found two usefull links to reconstruct the circuit:
https://oldamps.weebly.com/harmony-h307x.html
https://lectrolab.wordpress.com/lectrolab-models/r600/
The Lectrolab R600C is circuitry-wise identical to the Harmony H307X.
Last edited by Tumtrah on Fri Apr 23, 2021 10:26 am, edited 1 time in total.
- fenderheavy
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Re: Harmony H307X project
Good trade! Never heard of that model.
I have it’s more common sibling, the H306A. Got it for free about 20 years ago when I was picking up an old organ from a craigslist free ad. “Do you possibly have any other musical equipment?” Kind of deal.
Great sounding amp! You’ll dig it.
I have it’s more common sibling, the H306A. Got it for free about 20 years ago when I was picking up an old organ from a craigslist free ad. “Do you possibly have any other musical equipment?” Kind of deal.
Great sounding amp! You’ll dig it.
- Tumtrah
- PAT. # 2.972.923
- Posts: 94
- Joined: Thu Dec 12, 2019 12:09 pm
- Location: Hamburg area, Germany
Re: Harmony H307X project
Meanwhile the cabinet is fixed.
The damaged clothing is clearly visible but for now I will leave it as is.
Installed a (chinese?) Cream alnico speaker:
The damaged clothing is clearly visible but for now I will leave it as is.
Installed a (chinese?) Cream alnico speaker:
- Tumtrah
- PAT. # 2.972.923
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- Joined: Thu Dec 12, 2019 12:09 pm
- Location: Hamburg area, Germany
Re: Harmony H307X project
A look under the hood. Hefty modified... I'll have to gut the whole chassis and redo the electronics.
There is a fragmentary schematic on the back panel.
New chickenheads arrived.
There is a fragmentary schematic on the back panel.
New chickenheads arrived.
- Tumtrah
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Re: Harmony H307X project
The original OPT was changed at some point. Multi section capacitor missing...
New power chord
New power chord
- Tumtrah
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- Location: Hamburg area, Germany
Re: Harmony H307X project
I tried to recreate the component layout from pictures I found in the internet, including the weird ground wiring...
I additional installed an adjustable bias control pot.
The power supply multicap is still missing, I'll substitude the 3 blue caps in the future.
It works!
I additional installed an adjustable bias control pot.
The power supply multicap is still missing, I'll substitude the 3 blue caps in the future.
It works!
- Scout
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Re: Harmony H307X project
Very cool!
- DaddyDom
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Re: Harmony H307X project
Another H306 owner here and I LOVE mine! I often see them spoken of as blues-harp amps, as if they are no good for anything else but I love mine with guitar. Really super vibrato, too.
I hope you love yours!
I hope you love yours!
- Tumtrah
- PAT. # 2.972.923
- Posts: 94
- Joined: Thu Dec 12, 2019 12:09 pm
- Location: Hamburg area, Germany
- Tumtrah
- PAT. # 2.972.923
- Posts: 94
- Joined: Thu Dec 12, 2019 12:09 pm
- Location: Hamburg area, Germany
Re: Harmony H307X project
Yeah, I really love it! Today I took some time to plug in my Tellie and my Jag. Very nice sounding amp from clean to crunch with low side noise. The vibrato blew me away, once switched on I couldn'd turn it off again. I was lost in psychedelic heaven for a while!
Today I'm a happy guy!