EZ1290 modification
« on: July 25, 2019, 07:02:49 PM »
Hello I am using an EZ1290 board to make a preamp. I am not however looking for a Neve sound. So I was thinking of the idea of replacing the Carnhill transformers with some other brand. Would it still work ir the circuit doesn't work that way?

Also would you guys suggest me some alternative to the Grayhill rotary switch?

Thanks,

Tom


3nity

Re: EZ1290 modification
« Reply #1 on: July 27, 2019, 06:17:45 PM »
Sowter are great iron. Cinemag are amazing too.
I built a 1272 preamp using a 1290 pcb...look for jlm audio 1272 mod or rascal seven they used a lorlin or a pot...
Life is a path, death the destination.

Re: EZ1290 modification
« Reply #2 on: July 27, 2019, 07:25:20 PM »
Sowter are great iron. Cinemag are amazing too.
I built a 1272 preamp using a 1290 pcb...look for jlm audio 1272 mod or rascal seven they used a lorlin or a pot...


Do you think that Jensen would work?

ruffrecords

Re: EZ1290 modification
« Reply #3 on: July 28, 2019, 03:57:59 AM »

Do you think that Jensen would work?
The Neve output stage feeds dc current through the output transformer. The Carnhill transformers have a gapped core that will take this. So if you want to replace the Carnhill with something else yo need to take this into account.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: EZ1290 modification
« Reply #4 on: July 28, 2019, 10:24:46 AM »
The Neve output stage feeds dc current through the output transformer. The Carnhill transformers have a gapped core that will take this. So if you want to replace the Carnhill with something else yo need to take this into account.

Cheers

Ian


Thank you for your response, basically I am trying to make a preamp that has a cleaner and more transparent sound than Neve, also I want to have a fast transient response. I was thinking of achieving this by using a different transformer. What do you think of it?

chipss36

Re: EZ1290 modification
« Reply #5 on: July 28, 2019, 11:37:48 AM »
stower is making an air gap x former, the few reviews I have seen said it was rather dark sounding, however looks like they have done some work on it.
I myself have never used one.

"Sowter replacement design for Neve P/N L01166. New winding and core design for improved LF and HF response. Max output level +26 dBu at 50 Hz. Lead version is ideal for rack mounting. Size "OA" ( Width 40 mm.) replaces our type 9160.U"

its not cheep, I will wait till I see a glowing review before I jump...lol




 

3nity

Re: EZ1290 modification
« Reply #6 on: July 28, 2019, 12:29:27 PM »
6 years ago i heard a neve clone with sowter in and out...best sounding preamp...i did built a clone with cinemags.. Different beasts...sowter was far better in my opinion.
Life is a path, death the destination.

Re: EZ1290 modification
« Reply #7 on: July 28, 2019, 12:41:07 PM »
stower is making an air gap x former, the few reviews I have seen said it was rather dark sounding, however looks like they have done some work on it.
I myself have never used one.

"Sowter replacement design for Neve P/N L01166. New winding and core design for improved LF and HF response. Max output level +26 dBu at 50 Hz. Lead version is ideal for rack mounting. Size "OA" ( Width 40 mm.) replaces our type 9160.U"

its not cheep, I will wait till I see a glowing review before I jump...lol

Do you know how to improve the transient response on a neve ez1290? I want to have a faster transient

ruffrecords

Re: EZ1290 modification
« Reply #8 on: July 28, 2019, 05:11:55 PM »

Thank you for your response, basically I am trying to make a preamp that has a cleaner and more transparent sound than Neve, also I want to have a fast transient response. I was thinking of achieving this by using a different transformer. What do you think of it?
I suspect you will find this hard to do. Transient response is directly related to bandwidth and in the Neve the two major bandwidth limiting factors are the output transformer and the 2N3055 output transistor. You could probably source a custom transformer that would be better than the Carnhill - my first stop would be Jensen. Changing the 2N3055 is fraught with stability problems so I would not recommend you attempt it unless you are very experienced.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Spencerleehorton

Re: EZ1290 modification
« Reply #9 on: July 29, 2019, 03:45:55 AM »
I’ve made quite a few of these and they sound amazing, only problem now is if I do another batch I would need a pre order of at least 10 to do the next batch.
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!


ruffrecords

Re: EZ1290 modification
« Reply #10 on: July 29, 2019, 04:12:42 AM »
I’ve made quite a few of these and they sound amazing, only problem now is if I do another batch I would need a pre order of at least 10 to do the next batch.

I didn't know you made your own transformers. Cool. What are those ones and how do they differ from the Carnhill equivalent?

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: EZ1290 modification
« Reply #11 on: July 29, 2019, 02:27:24 PM »

Thank you for your response, basically I am trying to make a preamp that has a cleaner and more transparent sound than Neve, also I want to have a fast transient response. I was thinking of achieving this by using a different transformer. What do you think of it?

You could use a more neutral input transformer with the same ratio.  Plenty of options there.  The output, as Ian noted, is harder to find an alternative for though. 
However, you would need to change the circuit itself to affect the transient response and I don't think the 1272 is the circuit for doing that unless you're experienced or have a ton of time on your hands to grapple with the various interlinked parameters etc. 
You'd need to be messing around with current, compensation caps, substituting devices for faster ones... all while maintaining stability with the feedback loop closed.
Just get a faster amp to begin with and modify that if need be.

Just my $0.02

Spencerleehorton

Re: EZ1290 modification
« Reply #12 on: July 29, 2019, 03:15:11 PM »
Ian,

the LO1166 i made are to the original spec from CJ and in conjunction with a local transformer company down the road, Best Windings, I also have Brian Sowter a few miles away as well!!
I thought i was happy with the Carnhills until i tried my version, night and day, these ones are pretty big so loads of tone there, I would describe them as sounding much bigger and fuller, clearer mid range and more defined bottom end, and the top end definitely sounds more crisp.
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

3nity

Re: EZ1290 modification
« Reply #13 on: July 29, 2019, 03:40:26 PM »
Sowter has the inputs and ouputs.
Cinemag has inputa and ouputs too.
Hairball has inputs and ouputs too.
Good luck
Life is a path, death the destination.

3nity

Re: EZ1290 modification
« Reply #14 on: July 29, 2019, 03:41:49 PM »
You can try tip141c instead of 2n3055 too.
Life is a path, death the destination.

Re: EZ1290 modification
« Reply #15 on: July 29, 2019, 03:44:56 PM »
I’ve made quite a few of these and they sound amazing, only problem now is if I do another batch I would need a pre order of at least 10 to do the next batch.

I don't know If I told you, when I order last 4 ones, but I would need additional 4.  I saw on your site, that  you make input ones too ? How they are compare to the Carnhills ?

chipss36

Re: EZ1290 modification
« Reply #16 on: July 31, 2019, 09:12:46 AM »
I would be in for two if you wind em!

Spencerleehorton

Re: EZ1290 modification
« Reply #17 on: August 03, 2019, 12:27:29 AM »
Lampas, I’ve still not finished the enclosure to the 10468 yet, too many summer projects!!! Fet47 bodies and a skateboard ramp to finish!!!
They are on my list to finish, so I’ll let you know as I’m going to do a batch of about 10 x 10468.
The ones I’ve done so far sound amazing, again they are a different size to original do I’ve had to play around with the config, very happy.
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

shabtek

Re: EZ1290 modification
« Reply #18 on: August 09, 2019, 10:39:52 AM »
Output could be choke loaded and cap coupled to ungapped transformer or run unbalanced
"really fine players do not use stomp boxes or master volume, they match the amp to the room and turn it up to 11.  Stevie Ray, BB King, Albert King, Duane Allman, Dicky Betts, Louis Armstrong"
   -CJ


 

Related Topics

  Subject / Started by Replies Last post
EZ1290 finished

Started by Benny « 1 2 » The Lab

30 Replies
12755 Views
Last post August 24, 2009, 04:49:23 PM
by Audiotronic
1 Replies
1842 Views
Last post April 25, 2009, 07:23:43 AM
by rodabod
18 Replies
14071 Views
Last post November 26, 2011, 07:10:36 PM
by a zombie
14 Replies
5358 Views
Last post August 31, 2009, 11:18:55 PM
by 3nity