Harmony H307X project

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Tumtrah
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Harmony H307X project

Post by Tumtrah » Fri Mar 12, 2021 11:23 am

Traded this Harmony amp in for an accutronics reverb tank. It has a broken cabinet, changed/modified circuit, non original OPT, knobs and speaker.
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jthomas
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Re: Harmony H307X project

Post by jthomas » Fri Mar 12, 2021 3:18 pm

Looks like a fun resto project.

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Tumtrah
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Re: Harmony H307X project

Post by Tumtrah » Sat Mar 13, 2021 1:29 am

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.
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tribi9
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Re: Harmony H307X project

Post by tribi9 » Sat Mar 13, 2021 8:57 am

Tumtrah wrote:
Sat Mar 13, 2021 1:29 am
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.
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Its called particle board.

Good stuff. You should do up a new cabinet though. Particle board sucks.

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Tumtrah
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Re: Harmony H307X project

Post by Tumtrah » Sat Mar 13, 2021 11:55 am

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? :unsure: 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.

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fenderheavy
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Re: Harmony H307X project

Post by fenderheavy » Sun Mar 21, 2021 9:21 pm

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.

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Tumtrah
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Re: Harmony H307X project

Post by Tumtrah » Mon Apr 05, 2021 10:57 am

Meanwhile the cabinet is fixed.
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The damaged clothing is clearly visible but for now I will leave it as is.
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Installed a (chinese?) Cream alnico speaker:
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Tumtrah
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Re: Harmony H307X project

Post by Tumtrah » Fri Apr 09, 2021 8:47 am

A look under the hood. Hefty modified... :wtf: I'll have to gut the whole chassis and redo the electronics.
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There is a fragmentary schematic on the back panel.
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New chickenheads arrived. :)
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Tumtrah
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Re: Harmony H307X project

Post by Tumtrah » Mon May 17, 2021 10:43 am

The original OPT was changed at some point. Multi section capacitor missing...
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New power chord
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Tumtrah
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Re: Harmony H307X project

Post by Tumtrah » Mon May 17, 2021 11:14 am

I tried to recreate the component layout from pictures I found in the internet, including the weird ground wiring... :wacko:
I additional installed an adjustable bias control pot.
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The power supply multicap is still missing, I'll substitude the 3 blue caps in the future.
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It works! :)
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Scout
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Re: Harmony H307X project

Post by Scout » Mon May 17, 2021 3:24 pm

Very cool!

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Re: Harmony H307X project

Post by DaddyDom » Mon May 17, 2021 6:40 pm

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!

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Tumtrah
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Re: Harmony H307X project

Post by Tumtrah » Tue May 18, 2021 10:29 am

Scout wrote:
Mon May 17, 2021 3:24 pm
Very cool!
Thanks!

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Tumtrah
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Re: Harmony H307X project

Post by Tumtrah » Tue May 18, 2021 10:51 am

DaddyDom wrote:
Mon May 17, 2021 6:40 pm
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!
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! ;D
Today I'm a happy guy!

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