NJW Posted May 12, 2011 Share Posted May 12, 2011 So my amp has been starting to sound like it needs a little TLC recently because it has gone from 'BEST AMP EVER' to 'really good amp' lately (y'know... we all get excited when stuff sounds good). This means it's time to take it to the doctors, but before calling and making it's appointment I'd thought I'd open her up and see what was inside. To my surprise, I found that one of the Marshall 6550s in there has been swapped out for a weird old Leslie 6550 and I can only assume it was done by someone in the studio where it has been getting used sneakily thinking 'hmmm I need a spare 6550, i'll steal one and put this broken one in there'. Anyway, she is now gonna go for a full retube but I thought I'd take photos of the internals so they can be used for reference by any other Skunkworks owners, and I'll put more info here if anyones interested. Spot the odd one out... Grrr! Quote Link to comment Share on other sites More sharing options...
NJW Posted June 27, 2011 Author Share Posted June 27, 2011 I have listed this straight from the 'other' bass forum, but feel it's good information and I'm sure the original poster won't mind his knowledge being shared. Posted by Dave Ryan, who was part of the 'Skunkworks' team in the 80's. ------------------------------------------------------- I see a lot of strange things from time to time. As with all popular things, esp guitars & amps, there are a lot of myths & rumors out there. I wanted to give a little insight to the begining of Ampeg as it relates to the SLM erra of the "Harley Davidson" of bass amps, I was there. I started working @ SLM Electronics in 1985, I was the line assembly supervisor in the "Skunk Works" re-issue project. SLM Inc purchased the rights to Ampeg 1986. When we bought the company there wasn't much left. 2 tractor trailer loads of misc parts, documents & some amplifiers. There were about 50 unfinished MTI SVT-HDs & 100 MTI V-5s & some misc units, a couple of V-4s, some V-3s, a VT-40 etc... What SLM decided to do was build up any stock we had & get it on the market ASAP. So we built cabinets for the SVT-HDs chassis, we used the "Skunk Works" cabinets as we did not see the advantage of having to build 50 MTI style cabs, then building 500 SW cabinets. They were also missing back plate panels, so we used the "SW" panels that say "Made in America by SLM Inc 1400 Ferguson Ave". This had lead a lot of people to believe, later on down the road, that these are "SW" SVTs, they are not. They were assembled by SLME from left over MTI chassis. Myself & the chief engineer put these 50 SVTs together, biased & tested them, out the door they went. The 100 V-5s we had, were converted to bass amps by changing the preamp slightly, we had new face plates made for them to reflect the new model # [those were usually the only differences between Ampeg's guitar & bass amps anyway] We named them SVT-100s We did this very quickly to get Ampeg's name back in the main stream. Marketing started a campaign blitz in all the music magazines world wide to let everyone know SLM owns Ampeg & Ampeg is back. This kept the pubic busy for several months while we annexed some office space in our new 45,000 sq ft building, recently purchased for production of all SLM products. We tooled up & did all the wire preps, established our testing procedures, recruited personal from the assembly line in the factory & away we went. Everything was made in house. Woodshop made all the cabs, Engineering, Tolex, Chassis Assembly Test, Electronic assembly, Wave Solder, Wire preps, Customer Service, all under one roof. It took us about 9 to 10 months to complete the run of 500. Most of these were sold before they were made. The "Skunk Works" SVT-HDs were the first American made Ampeg's since Magnavox owned them in the 70's. There was NO "post MTI, pre SLM Skunk Works" SVT's. There is no such thing, they do not exist. So in my 23 years here I am not aware of any "rare jems". The only thing I can think of is the confusing 50 MTI SVT-leftovers we assembled & the 100 SVT-100's What ever else you hear to the contrary is rumor, speculation & myth. If you have the Ampeg history book, [dont know the page #] look at the picture of the Skunk Works crew. I am the guy in the front row on the left, behind me is George McKale, engineer, to the far right front row was the man who made Crate, Audio Centron & Ampeg huge players in the music industry, John Karpowitz. He died some years ago from cancer. He was the driving force behind SLM Electronics in the 70's 80's & 90's It was an exciting time @ SLM for a 26 y/o young aspiring bass player, it is only in the last 10 years or so I realized the importance of what we did, & how it impacted the music industry. It was a lot of fun & the moral & energy was indescribable. Everyone did the best they could & I believe SLM engineers did a great job of not only bringing back the Ampeg name, but to go way beyond that with a complete full line of tube & solid state amplifiers that set the standard for several years to come & put Ampeg back on the map. 2 Quote Link to comment Share on other sites More sharing options...
NJW Posted June 27, 2011 Author Share Posted June 27, 2011 Jerrold Tiers - ex ampeg employee --------------------------------------------------- "The SVTs of all flavors used output transformers from a company in Chicago called 'Electrical Windings", who were the supplier for the original SVT. That lasted until Electrical Windings were absorbed into another company, who then continued to supply them until recently. E-W made a number of other specialty transformers for the Ampeg line as well as the SVT transformers. In many cases, they had the original production documents still, and could re-produce the same unit essentially precisely. In fact, early on, the engineer who had designed the original SVT transformer was still there, and able to assure the parts were the same. Similarly, the faceplate extrusions were from another Chicago company called "Lightning Metals", another original supplier. In as many cases as possible, the original suppliers were identified from documentation, and used if the parts could be obtained from them. So in a way, the 500 were a more true "re-issue" than even the VR." Quote Link to comment Share on other sites More sharing options...
Gareth Hughes Posted June 27, 2011 Share Posted June 27, 2011 Nice one. Good to read a little bit of bass history. A mate of mine has a Skunkworks Ampeg, bout in LA many years ago when he lived there. Now residing in sunny Belfast, it needs a little bit of TLC too. Quote Link to comment Share on other sites More sharing options...
NJW Posted June 27, 2011 Author Share Posted June 27, 2011 Oooh thats interesting... Any chance you would be able to find out the number of it? I'm trying to see how many of the 500 I can track down and list their current relocation because, put simply, I am a [b][i]MASSIVE[/i][/b] nerd. Quote Link to comment Share on other sites More sharing options...
Clarky72 Posted December 15, 2011 Share Posted December 15, 2011 Hi, I have no 236 right here. It is truly the most amazing sounding amp I have ever heard. I would save it from my burning house over any other item I own... I used to own no 257 too, but it got stolen about a decade ago. S Quote Link to comment Share on other sites More sharing options...
73Jazz Posted February 18, 2012 Share Posted February 18, 2012 Here you have number 487, located in germany. This amp is my soundhome, best amp i have ever heard and my vintage fender basses Deliver the sound i was always dreaming of. Quote Link to comment Share on other sites More sharing options...
davywatson Posted January 19, 2013 Share Posted January 19, 2013 [member='davywatson'] Hi there, I'm the 'skunkworks' owner from Belfast - friend of Gareth's. Yes, my #448 is in need of a little TLC and is in the process of getting a re-cap. I also had it rewired for 240v. Does anybody know of a Power Amp & Pre-Amp schematic that would best resemble this amp? i.e. late 70's SVT with 6550a's. Quote Link to comment Share on other sites More sharing options...
73Jazz Posted January 19, 2013 Share Posted January 19, 2013 (edited) Try to contact Jerold Tierres on Talkbass, he is a source of knowledge and may be the right person for your question, as he formerly worked for Ampeg. He is a true gent and a nice person to communicate with. For 6550 you should choose Svetlana winged C, they are ...aaahm...'god' Edited January 19, 2013 by 73Jazz Quote Link to comment Share on other sites More sharing options...
Bassman Steve Posted January 19, 2013 Share Posted January 19, 2013 +1 for the winged C 6550. I have them in my Boogie Bass 400 and they are a great sounding valve. Quote Link to comment Share on other sites More sharing options...
Clarky72 Posted December 1, 2014 Share Posted December 1, 2014 So a year ago, strapped for cash I sold it. Been kicking myself ever since. Now on the lookout for another...if anyone has one, drop me a line please!!! Quote Link to comment Share on other sites More sharing options...
sean2969 Posted March 2, 2015 Share Posted March 2, 2015 I own number 232 it's a UK voltage, in excellent shape. Been in a live in flight case all its life. Bought from a guy near Swansea who was emigrating. It's not for sale! I've owned an early SVT2 non pro, which was made at about the same time,it sounded very similar. Also owned a Vietnamese VR which did sound good but had a transformer hum which I could never get rid of. I've compared my skunkworks to several USA made CLs they didn't come close in my opinion. I also have owned 236 but sold it on a few years ago, sorry Steve. Quote Link to comment Share on other sites More sharing options...
Ampeg Bass Posted February 13, 2020 Share Posted February 13, 2020 (edited) Anyone have a schematic for these things? I have 116 Edited February 14, 2020 by Ampeg Bass Quote Link to comment Share on other sites More sharing options...
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