Help needed in restoring a 73' SA-212

[[PJS]]

Hi!

I saw an add for a 73' (I think) Hiwatt SA-212 amp that was for sale in a local music store and the price was unbelievably low, only 700€. So I went to the store and found out that the price was so low since the amp wasn't actually in mint condition anymore because the previous owner had modified the combo in to a head by sawing the speakers off. The amp -part was in good condition tough and it sounded awesome so I decided to buy it anyway.

Now I'd like to restore the amp in it's original condition by rebuilding the wooden casing and installing a pair of good quality Faneish speakers in it. The problem is that I can't find any measurements for the casing. I'd need to know:
- The exact measurements of the combo
- How thick are the different parts?
- What wood should I use?
- How are the sides connected?
- Anything else I should know?

Can anyone please help me? I'm getting kinda desperate since I can't seem to find any info on how old Hiwatt combos were built...

PS. I'm new to the forum so...Hi. And sorry for the possible weirdnesses in my english since i'm not from an english speaking country.

[OldSchoolDave]

PS. I'm new to the forum so...Hi. And sorry for the possible weirdnesses in my english since i'm not from an english speaking country.

Howdy! I AM from an english-speaking country, but still speak with many wierdnesses .

I've got an SA212 from '79. I doubt that the cabinet changed much over the years, but hopefully someone will be able to verify that. My SA212's currently in storage. Are you in a big hurry for the dimensions?

In general, I believe the combo cabs were built like the speaker cabs: out of 3/4" void-free plywood (baltic birch, if you've got it - with marine glue). Corners are finger-jointed and then rounded with a router. Mine's in need of a facelift, but I could get you some pictures to give you the basic idea. Let me know if that would help.

It might also help if you can post pictures of your butchered cabinet, so we can tell what you have to work with.

regards,
Dave

[mikhailwatt]

Corners are finger-jointed and then rounded with a router.

I believe most (if not all) the Hylight cabs featured rabbet joints with internal reinforcing.

This based on pics of some damaged-in-shipment cabs in which you can clearly see the joint separated.

[OldSchoolDave]

Corners are finger-jointed and then rounded with a router.

I believe most (if not all) the Hylight cabs featured rabbet joints with internal reinforcing.

Yes, but they were done with human fingers, hence "finger-jointed" . I hereby retract my previous statement (blush).

Dave

[dhare]

For us Brits that is a rebate joint.

[[PJS]]

I'll post some pictures for you later. And in exchange for all the help and kindness i'll also post some pics/comments as my little restoration project progresses...

I took some measurements from the remaining half of the amp:
The top and bottom:
27x12 cm (11,8x27,6 inches)

The sides:
22x12

Front and rear panels:
22x27

The speaker placement is still a mystery. And are the front and back panels also made out of 18mm (3/4'') plywood? All of the sides seem to be fortified with 18x18mm (1x1'') wooden "braces".

The rear panel's ported right?

Feel free to fill me in on the gaps and to correct me if im wrong.

Update. Based on an old Hiwatt catalog I found on the Mhuss's page I found that the SA212 combo's measurements are 22''H 27''W 12''D. Alltough I'm not certain since the amp in the catalogue has a "Custom Hiwatt 50" text on the front plate but mine doesnt. My amp's got a text saying "Custom built" written small in the left side next to the power, stand by and polarity switches.

[OldSchoolDave]

My amp's got a text saying "Custom built" written small in the left side next to the power, stand by and polarity switches.

Mine has similar writing. Here are a couple of pictures, just to get you started:





(note: the celestions stayed back with the previous owner)



Dave

[[PJS]]

Hmm... funny it doesn't seem to be wider than its height even tough the catalogue says it's H 22 and W 27

Is the part with the amplifier isolated from the speakers?

[ThunderOne]

Now I'd like to restore the amp in it's original condition by rebuilding the wooden casing and installing a pair of good quality Faneish speakers in it. The problem is that I can't find any measurements for the casing. I'd need to know:
- The exact measurements of the combo
- How thick are the different parts?
- What wood should I use?
- How are the sides connected?
- Anything else I should know?

Can anyone please help me? I'm getting kinda desperate since I can't seem to find any info on how old Hiwatt combos were built...

Hello!
Allow me to contribute my $0.01 worth of advice. If making a new cab yourself is not an absolute priority and if you want to get your amp and speakers in the best possible and closest to original as possible enclosure, I suggest you get a quote from Jeff Swanson. I've had a very positive experience in dealing with this gentleman and I highly recommend him.

Cheers!

Franz

[[PJS]]

I thought about that for a while. But I figured that building the thing myself isn't going to be insanely difficult and the price will be low compared to ordering the cab from the US and shipping it to Finland is going to cost a bit too much. But thanks anyway.

[[PJS]]

And it'll also be fun to do it my self.

[OldSchoolDave]

Hmm... funny it doesn't seem to be wider than its height even tough the catalogue says it's H 22 and W 27

I believe it is wider, but not sure if it's 5" difference. I'll try to get you rough dimensions in the next couple of days.

Is the part with the amplifier isolated from the speakers?

No. The tubes hang down into the speaker area. The upper back panel protects the tubes and has a 1" (or so) lip on it, but does not completely seal the compartment. In the closeup pic, you can see the slimmer plywood to which the chassis is screwed. That whole assembly slides into place and gets held in place with a couple of screws.

For reference, here is my SA112, with the upper back panel and chassis removed:



Dave

[[PJS]]

Thanks!

I've made some preliminary drawings based on the assumption that the cabs 12Dx27wx22h but i'm stilll a little doubtfull about the height. 22'' seems too little. The front baffle's propably 3/4'' and the rear baffle's propably about 1/2''. There's also a 1'' lip on the front and the front baffle's attached to the 1x1'' supports that go around the enclosure exept the top front.

I'm propably putting a pair of 12'' Weber F12 speakers on the amp since I heard that they're closer to the original Fanes than the Re-issue crescendos.

Im also posting some pics of the amp in its current state next week.

[OldSchoolDave]

Finally got the opportunity to swing by the ol' Hiwatt Warehouse and measure my SA212. Please don't take these as gospel, as I did not have any calipers, micrometers or lasers available and the radiused corners can result in some rounding (pun intended). Here's what I got with my trusty 2 dollar lumberyard tape, measuring to the outside of finish material:

Overall dimensions: 27 7/8" wide x 22 1/4" high (not including skids) x 11 1/2" deep.

The front bezel is nominally 1 1/2" all around. There's a 3" void for the chassis and the overlay strip (aligned with the chassis void) is 1/2" thick x 2 5/8" high.

The baffle is 3/4" thick and is set back from the front bezel 13/16". Battens for the baffle are approximately 1/2" x 1/2".

The rear panels are 1/2" thick. Both have nominal strips of 3/4" x 3/4" x 23 7/8" long material applied to create the "lip". Battens at the rear panels are 3/4" x 3/4". The upper panel is 7 15/16" high. The lower panel is 6 15/16" high.

Hope this helps!

Dave

[[PJS]]

That helped alot thanks. I'm propably going to buy the materials next week and I hope that the project will be completed by the end of June so that I can use it when my band goes to studio...