Ormat reverb

Cliff Cooper's unique OR80, OR80 Combo, OD80, Graphic 80, OR100, Hustler Combo, OD120, OR120, OR120 Combo, PA120, Graphic 120, OR200, Reverb, 2x12, 4x12

Ormat reverb

Postby DavePedal on Sat Mar 12, 2016 4:26 pm

I'm restoring an Ormat reverb. It has no cabinet or spring unit. I need to match the right type of unit. I have a Hammond Gibbs type K unit which as an input impedance of 8 ohms and an output of 500 ohms, and I wonder if this might match. The tubes in it are 2 x ecc82 ans a ef86. The indicator lamp is broken and runs from the heater supply. It is also missing a Rendar jack socket with a white bezel.
I think there have been some posts on these in the past. Are there any members out there that have a 69-70 reverb and can identify the spring unit in theirs.
I am making a replica sleeve for it. I think it had the larger picture frame type rather than the thinner ones. This is because it has slots for mounting rather than holes.
I'd lobe to find some older type 1 pin plastic corners for the sleeve, but that's long shot.
This could be an interesting project, and I think it might have some value when it's finished.
I'm checking with Jeff at Matamp to see if they have any records on it. It's been buried since 1975 and does have a historical link to a few bands that used the same backline PA management pool as Fleetwood Mac, although it can't be one of the original Mac units.
I love getting these old things running again.
Any help will be great! Dave.
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Re: Ormat reverb

Postby Gladmarr on Sun Mar 13, 2016 2:06 am

Here's where you can order the correct corners. That's a start. http://www.voxshowroom.com/northcoast/referring/corner.htm
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Re: Ormat reverb

Postby bitbrain2101 on Fri May 20, 2016 7:33 pm

Does the reverb unit have a transformer for the input side of the reverb tank ? Then 8 ohms is ok, but 500 ohms at the output seems a little low for tube circuits. Please give us some pics of this rare gem.

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Re: Ormat reverb

Postby DavePedal on Fri Jul 01, 2016 10:29 pm

There are 2 transformers in it. One is the power plus heater voltage etc, the other is just a massive choke. It doesn't use a matching transformer. Valve compliment is 1 EF86 and 2 ECC83s.
I've got it powered up and I'm not getting much signal through to the tank. The output of the tank seems pretty loud if I tap it, but there is a significant hum. I know that one of the grounds is lifted off the tank. I think I shall get it across to my mate Chambonino to see if he can get it running properly. Jeff at Matamp said "they can hum like a bastard" and the original reverb tank hanging rubbers were from Tandberg tape recorder drive belts, which is unfortunate because I used to have one. The heater voltage has a slider trim pot instead of a skeletal, so it might be this will adjust the hum level?
The serial no. is 014 which is the earliest one I can find pictures of anywhere. According to the owner who had it dark holed for 40 years it had the thicker picture frame sleeve. This got skipped in the 1970s (along with the tank) when the unit fell out of the sleeve. They only used it to pack the PA speakers tight in the van! So he took the unit home and there it stayed.
How many of these still exist out there? Has anyone any idea?
I have made a new sleeve as correct as possible with original style corners and I even have an original Cooper Mathias badge for the back. Pity the tolex looks so bright Orange.
I'd love to see a list of known serial nos of these. The only two I've seen are 015 and 038.
At least it looks like it will live again, and because it is so rare I'm trying to keep all the original components.
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Re: Ormat reverb

Postby bitbrain2101 on Sat Jul 02, 2016 6:37 am

I have posted the schematic of an OR80R here
http://s1282.photobucket.com/user/bitbrain2101/media/OR80Reverb2_zps8727e798.jpg.html
Perhaps you can compare the reverb circuit, because it has no matching transformer at the reverb tank input. The EF86 in your Ormat reverb could possibly be an additional preamp stage at the input. I have written the Accutronics part-no. from the original reverb tank in the schematic. I also had some hum problems with the OR80R, but I could fix it with a proper ground wiring.

regards, bitbrain2101
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Re: Ormat reverb

Postby DavePedal on Sun Jul 03, 2016 1:37 pm

Thanks for that Bitbrain. It is very similar, and as you say, with a gain stage before using the EF86 pentode. Jeff said that they did 2 versions, this one was designed for a mic input.
I have a 4FB3 type tank which has a longer delay, but the same input / output impedance, so it should be OK. I don't know if the valves are good or not, because I fished them out of a box of spares. The EF86 is a Mullard though.
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Re: Ormat reverb

Postby DavePedal on Mon Mar 27, 2017 1:35 pm

I have this up and running now. there were only a couple of resistors missing. The slider switch was beyond use and I had to replace it. I had to repair the front panel with a piece of traffolyte where an XLR socket had been fitted. I sourced a period correct tank having been given advice from some forumites here. I also have mounted the tank by hanging it in the original manner using an elastic sling. The originals used Tandberg tape recorder drive belts.
I didn't have to replace any components, and with the help of my pal Chambonino got it running again. There doesn't appear to be any hum problems, and it has a bright sound. The tone control seems to work backwards like a treble cut, and there's loads of depth on the reverb control.
I built the new sleeve to as close as possible to original, although the tolex is quite bright. I also had a Cooper Mathias badge to go on it.
This is serial no. ORE 014. I have seen pictures of ORE 015, but nothing earlier. I think the date code on the PS capacitor is 1970.
I've found it hard to find out how many other units are out there, and how many were made. At least this one has been brought back to life after 40 years in hiding.
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Re: Ormat reverb

Postby DavePedal on Wed Mar 29, 2017 2:06 pm

Can someone help me post some pics of this here? This thing sounds fantastic and is great for driving the amp head whether you have the reverb turned up or not and the reverb has so much depth and clarity to anything I've used before.
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Re: Ormat reverb

Postby Gladmarr on Thu Mar 30, 2017 2:47 pm

I would love to see pics of this now that you've put all that work into restoring it. If you have pictures uploaded somewhere on the web, you should just be able to use the {Img} button above and place the URL of your pictures between the markers that appear.

Here's a pic of mine on top of some other stuff.

Image

In fact,if you click the button in the corner to quote my post, it will show you the syntax behind how I posted my image.
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Re: Ormat reverb

Postby DavePedal on Thu Mar 30, 2017 3:28 pm

What's the serial no of yours? Is it ORE 015? I haven't got an image hosting anywhere. Can someone email me for the pics to post them for me?
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Re: Ormat reverb

Postby spangled99 on Wed Apr 05, 2017 5:21 pm

Here is mine.

Some things to note - there are old hooks at the side from which at some point the Hammond Gibbs pan was suspended. It is now screwed directly to the box.

It is marked ORE39 inside, but has an OA serial number of OA7137

I haven't had this plugged in for a long time. I recall it made a whining noise for some reason.

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Re: Ormat reverb

Postby DavePedal on Thu Apr 06, 2017 1:18 pm

Great pics, spangled! Yours is the only other one I know about apart from Gladmarrs, and yours is the latest. Mine has the earlier Ormat knobs and the earliest serial no, but all the components look the same.
As for the strange noise, have you tried putting some screen cans on the valves? That ef86 might be quite sensitive. Just a thought although I doubt it will solve it.
Are there really ONLY THESE ones here on the forum? Or anywhere else!
Thanks, Dave.
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Re: Ormat reverb

Postby skumberg on Fri Apr 07, 2017 8:53 am

Dave sent me this picture of his Reverb Unit

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