HT-20 Combo - Opening the back?

[Sonofarich]

I've got a HT-20 combo that I've been playing with and decided to take the back panel off and check out the tonal differences. Since I have been playing small venues mic'd, I thought this might be a kewl idea. Definitely gives a more airy feeling and more pronounced highs. I think I might like it for the style of music I've been playing lately. If I play any harder stuff, I'll screw it back on.

So, my question...is there any structural integrity issues with doing this?? I don't think this amp was made to be convertible and I would guess that I need to pay particular attention to not damage the components, but otherwise I think the cabinet is meaty enough...right?

I realize most people probably prefer/need the tighter bass response with the back on, but for the style of music I'm playing a more Fender-ish tone is ok.

Has anyone else tried this? Your thoughts??

[Hendog]

You should be fine.

Some open back cabs are really open. The cab is quite sturdy.

[Sonofarich]

Yeah, without the back on the HT-20 is wide open...not much left covering. But, I agree that the cabinet is pretty sturdy (even if it is MDF) and if I'm careful I should be OK.

[Sonofarich]

Has anyone else pulled the back off their BS combo??

Curious to hear what you think of the tone...

[Iwan]

I've made my HT40 about 2/3 open. I just bought a new 12mm mdf plate to make a new backplate and painted it black. In conjunction with a Classic Lead speaker and Tungsol 12AX7 V1 tubes, the amp got a major upgrade. You are correct that the amp becomes more transparent (Fenderish) sounding and removes some of the low end, which in my playing style is just what I need. The low end is somewhat compensated by the Classic Lead speaker though. But if you want a tight/direct low end stick with the closed back. I'll keep my ht40 with the open backplate, love it.

[Sonofarich]

I decided to take your advice and add a little structural support by reinforcing the top with some 1/2" birch. A little sanding/paint and voila...



Still leaves it wide open and preserves that transparent sound. I'm pleased.

Forgot to mention that I also added a strip of heavy duty (black) velcro tape (the fluffy side) to each side of the new back to act as a cushion between the wood faces. The original back has a thin strip of foam(?), so I wanted to make sure I had some sort of barrier. Works well.

[Sonofarich]

Update:

Ordered a WGS Vet 30 today to see if I can improve the tone a little. I'll post some clips before/after when I get it loaded.

[Iwan]

My backplate is slightly different. I have the closed part at the bottom and at the sides the plateruns up like a U shape. Same effect but more conventional. I'll try to upload a picture tomorrow.

EDIT: that will be next monday, my amp is in the rehearsal room.

[Sonofarich]

Got the Vet 30 today. Three words...

What a deal!

See my new post for details.