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Early 70's Delta Concept 1 Amp & Speakers Effects Pedals, Units & Accessories
Old 10th October 2010
  #1
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Early 70's Delta Concept 1 Amp & Speakers



First off newbie here stopping bye to say Hello and starting off with asking about this old set.
Anyone know anything about these rare and old big-buck Amps?
Designed by Harvey Gerst and maybe only about 100 made?
Sold for 6000 to 8000 thousand dollars in 1974?
Used by the Dobbie-Brothers?

Last edited by max2343; 10th October 2010 at 11:54 PM.. Reason: mistake
Old 11th October 2010
  #2
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Teddy Ray's Avatar
 

eh...Harvey Gerst is a member here...
Old 11th October 2010
  #3
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Ya I know and that's what led me to this site. I found an old ebay transaction from about a month or 2 ago. A guy had a real nice Delta Concept 1 head that he sold for 4000 dollars after having it for 15yrs. He explained a lot of history of this amp and also explained a lot about it and who used them.
Anyways that man just emailed me back and he said that he also just gave a Delta Concept 1 Head to Harvey for a trade on some studio time.This is getting to be soo kool for me.
Hope he catches this thread
Old 11th October 2010
  #4
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Harvey Gerst's Avatar
Yup, the Delta Concept I is in our studio and everybody loves it. It's only the head, so I'm still looking for the original cabinets to go with it. The speakers present a 1.2 Ohm constant impedance load to the amp, so the speakers can't be used with any other amplifier.

It's now 36 years old and it was way ahead of its time - with some features only starting to appear in current amplifiers. I doubt the figure of a hundred units out there; more like maybe 10 or 15.
Old 11th October 2010
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Old 11th October 2010
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Old 11th October 2010
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Old 11th October 2010
  #8
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Old 11th October 2010
  #9
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I know about the load on the cabs. The ported closed back 2x12 cab comes in at a 3.7 to 3.8 ohm load and the 4x10 open back cab with 4 -8ohm speakers is coming in at a strange 2.6ohms?
Great to get your attention Mr.Harvey. I've just found out about the Amp that you designed and now I know what I have here in my bedroom. I feel kinda special to be the one that for some reason these ended up with me maybe on their way to you.
They sound fantasic well at least the 2x12 cab does. That's the only one I've played because of the weird load on the other cab.
I did hook up the 4x10 cab onto a S.S. Marshall only because of the load and it does sound great also but the S.S. after about 45min started cutting out and sounding like a tremelo.
Can you tell me about the Amp & Speakers and maybe to whom the other sets went to? What was the reasoning behind a 2x12 & 4x10 set-up?
What is a Hi-Power Transducer?
Old 11th October 2010
  #10
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Harvey Gerst's Avatar
Quote:
Originally Posted by max2343 View Post
I know about the load on the cabs. The ported closed back 2x12 cab comes in at a 3.7 to 3.8 ohm load and the 4x10 open back cab with 4 -8ohm speakers is coming in at a strange 2.6ohms?

Great to get your attention Mr.Harvey. I've just found out about the Amp that you designed and now I know what I have here in my bedroom. I feel kinda special to be the one that for some reason these ended up with me maybe on their way to you.

They sound fantastic well at least the 2x12 cab does. That's the only one I've played because of the weird load on the other cab.

I did hook up the 4x10 cab onto a S.S. Marshall only because of the load and it does sound great also but the S.S. after about 45min started cutting out and sounding like a tremolo.

Can you tell me about the Amp & Speakers and maybe to whom the other sets went to? What was the reasoning behind a 2x12 & 4x10 set-up?
What is a Hi-Power Transducer?
Well, the cabinet and speaker design were created to only work with the Delta amplifier. The total impedance load was designed to be 1.33 Ohms, but the idea was to make the load impedance constant - without the resonant peaks of other speaker systems.

The 4x10 cabinet was open back and had a resonant peak around 90 Hz (which meant the impedance shot way up at that frequency). The 2x12 closed-back ported cabinet had two large peaks about an octave lower. Since they were wired in parallel, as one cabinet's impedance went up, the other cabinet acted like a shunt and kept the overall impedance pretty constant.

That made the system pretty damn loud, but it required an amp capable of delivering its full output into almost a dead short. The Delta amp was able to put out over 300 Watts into this load, but we had to use heavy duty AC power cords as connectors between the amp and the cabinets, since normal speaker cables would get way too hot. The 2x12 is designed to sit on the floor, with the 4x10 cabinet sitting on top of it. That way, the 4x10 speaker cable could be made shorter - an important factor when dealing with very low impedances and very high power.

A "transducer" is something that converts one kind of energy into another kind of energy; it's a fancy name for what a speaker does. It converts electrical energy into mechanical energy. And at 300 Watts, they better be capable of handling high power, hence the name.

I don't wonder that the 4x10 box almost blew the Marshall head; I'm kinda surprised it lasted 45 minutes with that kinda load.
Old 11th October 2010
  #11
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That's pretty kool. Thanx's for clearing that up. I'm not really into 10" cabs. What else you got? Any old Vintage Gibson's/USA BC Rich's or Marshalls? Do you really want to do this on the web? how about a P.M. or by phone?
Old 12th October 2010
  #12
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Hello Mr. Harvey. I must say you have lived an Interesting life and you seem like a nice guy. I enjoyed talking with you.

I'm lucky life tossed me into your Path and I'm vary lucky life helped me to get the other half of an Great Amp that you Created Reunited with you.
Old 13th October 2010
  #13
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Quote:
Originally Posted by Harvey Gerst View Post
I "seem like a nice guy"? Hell, I AM a nice guy! Just ask my wife.

(Uh wait, don't ask my wife. Just ask anybody else.) heh

Sounds like I'm in for a 955 mile road trip.
Sounds good to me. If you plan on coming out this way we are going to go out for real good time. Chicago Style. Ya-up-for-it?
Old 14th October 2010
  #14
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So Harvey, have you come up with anything you might want to trade for these cabs or have you any Idea what you are willing to pay for them?
What are you offering?
Old 15th October 2010
  #15
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Sorry but No Thanks on that one. What else you got?
Old 15th October 2010
  #16
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So far these cabs are right at home under my Fallen Angel 180 6-EL34 Tube Monster and kinda look good too in my Bedroom next to my Mirrored Canapy Water Bed and really fill the room with Heavenly Bliss when I'm jamming-out and dreaming that I'm a Famous Rock-Star and besides its the oldest vintage cabs I got.

Sorry but I'm not willing to part with them for a 200 to 300 Dollar Head.
They do look great here, don't they.
Old 18th October 2010
  #17
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Mr. Harvey. The Laney amp is from the 70's? and the 75 cab, what speakers does it have inside. Are they originals?
The Ampeg Cab what year is it and what speakers does it have?
Can I see photos?
Do you have any 4x12 Marshall Cabs
or maybe a Nice Guitar?
How about 2 Marshall 4x12 cabs from the 70's just like the Deltas.
I mean from the same Era. Vintage for Vintage and the Laney Head.
Or how much cash are you offering
Old 18th October 2010
  #18
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You know what forget it. I'm not playing this Game. I'm not waiting 2 or 3 days for a simple answer. I talked with you on the phone and you told me that you were waiting for your son to return because all your nice stuff was in studio A.
Then you were going to figure out what you were going to trade me.
That didn't happen and I'm tired of this game. I don't want or need crap or stuff that someone uses when they first start out. These cabs are Vintage early 70's and I've already made a simple rewire of the goofy 2.2 ohms of the 4-8 ohm 10's cab to a simple 8 ohm arrangment and I going to swap out the 8 ohm Eminance 2x12's with 2 G12 Vintage 30's 16 ohm speakers wired to 8 ohms for a total of the both for a regular 4 ohm load.
Sorry but I tryed and I'm a nice guy but not stupidtutt
Happy Trails & Good luck in your Search.
Old 18th October 2010
  #19
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Harvey Gerst's Avatar
You own some great cabinets and I hope they continue to bring you as much pleasure as I had designing them. The 4x10 should be above the 2x12 for best acoustical balance. At least, that's the way I designed it.

Sorry it didn't work out.
Old 18th October 2010
  #20
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Quote:
Originally Posted by max2343 View Post
You know what forget it. I'm not playing this Game. I'm not waiting 2 or 3 days for a simple answer. I talked with you on the phone and you told me that you were waiting for your son to return because all your nice stuff was in studio A.
Then you were going to figure out what you were going to trade me.
That didn't happen and I'm tired of this game. I don't want or need crap or stuff that someone uses when they first start out. These cabs are Vintage early 70's and I've already made a simple rewire of the goofy 2.2 ohms of the 4-8 ohm 10's cab to a simple 8 ohm arrangment and I going to swap out the 8 ohm Eminance 2x12's with 2 G12 Vintage 30's 16 ohm speakers wired to 8 ohms for a total of the both for a regular 4 ohm load.
Sorry but I tryed and I'm a nice guy but not stupidtutt
Happy Trails & Good luck in your Search.
How old are you?
Old 18th October 2010
  #21
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12hehdfegad
Old 18th October 2010
  #22
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I really wish people would refrain from insulting the senior (both in age and experience) members here. It really pisses me off. Learn some manners, son.

Sorry Mr. Gerst, for having to put up with people like max.. Some people are just common.

If I ever come across these Mr Gerst, you have my word, I will just give them to you. You deserve it.
Old 19th October 2010
  #23
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Quote:
Originally Posted by Teddy Ray View Post
I really wish people would refrain from insulting the senior (both in age and experience) members here. It really pisses me off. Learn some manners, son.

Sorry Mr. Gerst, for having to put up with people like max.. Some people are just common.

If I ever come across these Mr Gerst, you have my word, I will just give them to you. You deserve it.
How did I Insult Mr. Harvey or anyone?
I'm Common?tutt & your What
Now were name calling. What are you, 10?
Old 19th October 2010
  #24
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Harvey Gerst's Avatar
Thanks guys, but let's just drop it. He doesn't really know, or care, who I am - and that's fine with me. It was just a deal that didn't work out - for whatever reason. He made some accusations that weren't true, but you all know me, so it didn't really harm me in any way.

As I said (and meant sincerely), he has some fine cabinets and they should give him years of pleasure. And I had a lot of fun designing that particular system, so let's just let this thread die.

I'll either find another set, get Jeff Baxter to open his warehouse when I see him, or make a couple of new boxes.

Thank you all for your support, but let max2343 enjoy his treasure.
Old 1st June 2011
  #25
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Harvey Gerst's Avatar
And now, the rest of the story...

Well, Max contacted me a week or so ago, and said he found some Sunn cabinets on eBay that he'd be willing to trade for the Delta cabinets. I bid on the Sunn cabinets and won them. It was time for a road trip. Friday morning, I piled into the car and headed out from Texas for Channahon, Illinois to pick up the Sunn Cabinets. Stopped in Normal, Illinois for the night, then picked them up and headed for South Beliot, Illinois (near the Wisconsin border) Saturday morning.

Max was happy with the Sunn's, and the Delta cabinets looked almost brand new. I loaded the Delta's into the trunk and off we went for Texas, fighting rain storms. We spent the night in Kearney, Missouri, got a flat in Ardmore, Oklahoma, but made it to home around 6 pm Sunday night.

Today, we spent a few minutes putting the wiring back to correct impedance, and fired the amp up. Gawd, I had forgotten how great this combo sounded!!! Alex was totally blown away.

So without further ado, here is the restored Delta Concept One system:
Attached Thumbnails
Early 70's Delta Concept 1 Amp & Speakers-delta1.jpg   Early 70's Delta Concept 1 Amp & Speakers-delta2.jpg  
Old 1st June 2011
  #26
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Mr. Gerst,

Great to see you with your rig in tact and sounding as you always knew it would.

Did you ever make a Delta 8/10" cab facing V style four speakers a side?

I use to gig with a Delta speaker column and it sounded great. I played a strat thru an old Dan Armstrong Orange Squeezer into my trusty 63 blond Fender Bassman brain into the Delta cab. The tone was to die for. That was some 30 years ago.

Thank you
Old 1st June 2011
  #27
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Harvey Gerst's Avatar
Quote:
Originally Posted by toneguru View Post
Mr. Gerst,

Great to see you with your rig in tact and sounding as you always knew it would.

Did you ever make a Delta 8/10" cab facing V style four speakers a side?

I use to gig with a Delta speaker column and it sounded great. I played a strat thru an old Dan Armstrong Orange Squeezer into my trusty 63 blond Fender Bassman brain into the Delta cab. The tone was to die for. That was some 30 years ago.

Thank you
OMG, I forgot all about that one. I didn't even know any of them actually escaped from the factory. It was pretty clever and damn nice sounding.

We had a lot of 10's in the factory, and I decided to build a simple, low-cost PA cabinet with wide dispersion that would be used for both the audience, and enough spill to be used as stage monitors at the same time. Using a pair would give you a 16 x 10" PA system that could handle a lot of power.

Yeah, it would have been a killer guitar rig.
Old 1st June 2011
  #28
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Awesome!

That was my first band when I was like 17 or so. We had both cabs. Used them for the PA.

After we broke up I kept one cab and it was pure heaven with the Bassman. And yes, the dispersion was an added bonus.

Thanks again Mr Gerst.

PS. We called it the Sweet Sixteen.
Old 19th January 2012
  #29
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I hope they stay with u. I'm sorry for the bad first Impression what can I say Ive got some problems but after a while I wanted those mint cabs to go back with u Harvey. Its Funny how life throws ya a cruve. At first I saw Dollars signs because I don't have it that good but after a while I realized that they belong with u and just wanted to pay it Foward and do a simple low dollar trade. Im sorry your trip had problems right from the start with car problems and then all the storms but in the end it all workrd out good. P.S. Can u please send me some photos of u and maybe your Family next to the reunited Stack.
Old 19th January 2012
  #30
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Harvey Gerst's Avatar
No problem; I'm just glad to see at least one of my babies is now complete and restored to its original glory. Over many decades of designing stuff, I always seemed to miss keeping many of my creations. I guess I now have a chance to actually collect some of my old designs. Again, thank you for letting me restore these cabinets and reunite them with their proper head.
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