Chinese Neve LO1166 Clone - Golden Age Pre-73 Output transformer

[fluidartmedia]

Hi Whoops

I actually picked up a pair of the Gap Pre73 and later a pair of the matching EQ for them. A friend of mine changed out the stock input transformers for some Cinemags, and the improvement was noticeable. I unfortunately didn't try to take any measurements before the swap, but the audio passing through them now has an excitement to it that it didn't before.
I'm actually trying to find time to replace the caps in the EQ with polystyrene ones (as you can see they're inconsistent from one to another, preamp as well), so if you tell me how to go about a good way of measuring before & afters I'd be happy to post the results.

I've often wondered what the difference would be with using actual Marinairs, but I was told that the Cinemag (I wanna say 9045s? Don't quote me... ) are basically just the American version.
I'd actually be interested in building a replica 1073; the GA ones sound okay but could always be better.

Thanks for all the effort you put into this!

 

[Whoops]

Hi, thanks for your message

so if you tell me how to go about a good way of measuring before & afters I'd be happy to post the results.

Well, you could use REW to measure it.
It sends a sweep signal to the input and measures the signal at the output.
It's easy to do.
Some recording of before and after would also be cool, the problem is that the performances would be different. Maybe send some music to the input and record the output...

I've often wondered what the difference would be with using actual Marinairs, but I was told that the Cinemag (I wanna say 9045s? Don't quote me... ) are basically just the American version.

I don't know about that.
Carnhill are supposedly to be copies of the originals Marinairs, I don't know if thats actually true or not, only rewinding one would tell that.

I know that the Sowter transformer is not an exact replica it's actually an "Improvement" it used a bigger core do it saturates less in the low end.
Technically it's an improvement but some people will consider that it will not deliver the "original" sound so it's worse for them, I understand both points. Sowter makes high quality "replacement" transformers not "clones".

Cinemag is a great company and for sure they do quality transformers, it it's an exact clone or a replacement I dont know

 

[Rob Flinn]

Whilst I agree that these Chinese transformers aren't like Marinair sound or quality wise. I have used these transformers (that people have given me when they replaced them on bits of gear) before where a Neve sound wasn't wanted, but I wanted something a bit more vibey & they actually worked & sounded ok for the purpose I used them.

 

[Whoops]

Hi Rob, are you referring to the input transformers or output transformers? Or both?

 

[Rob Flinn]

The output transfomers. I've never been given the input transformers to play around with, but the mic inputs I probably wouldn't use anyway.

 

[Whoops]

The output transfomers. I've never been given the input transformers to play around with, but the mic inputs I probably wouldn't use anyway.

I have 2 of the China Mic input transformers I will try them in some Bo Hansen DI boxes, might be good for a DI

 

[3nity]

I have 2 of the China Mic input transformers I will try them in some Bo Hansen DI boxes, might be good for a DI

Do you know the pin out on those input transformers I have a pair and I have no way to ID them

 

[Whoops]

Do you know the pin out on those input transformers I have a pair and I have no way to ID them

I don't have the transformers here at the moment, but isn't there a sticker on the transformer with the windings diagram? I have a recollection there's a sticker there...

If there isn't a sticker maybe the pinout follows the the Marinair/St Ives L10468 or Carnhil VTB9045, measuring the DC resistance on the windings will give some idea on the pinout

 

[3nity]

Will try to find out. Thanks

 

[fluidartmedia]

Do you know the pin out on those input transformers I have a pair and I have no way to ID them

I only had one input transformer with a sticker, but this is it. Hope that helps

 

[Whoops]

Thanks for the photo, so the pinout in numbered diferently than the Marinair/St Ives input or the Carnhill VTB9045.

Chinese



Carnhill VTB9045



Marinair/St Ives on Neve schematic





I have some doubts which are primaries and secondaries on the Chinese transformer.
I don't know if the primaries are 1-2 3-4, or 9-8 7-6, but it's easy to test as it's a step up transformer

 

[fluidartmedia]

Thanks for the photo, so the pinout in numbered diferently than the Marinair/St Ives input or the Carnhill VTB9045.

Chinese

View attachment 91538

Carnhill VTB9045

View attachment 91539

Marinair/St Ives on Neve schematic


View attachment 91540


I have some doubts which are primaries and secondaries on the Chinese transformer.
I don't know if the primaries are 1-2 3-4, or 9-8 7-6, but it's easy to test as it's a step up transformer

I remember this being an issue when they were being installed - in fact the Cinemag that replaced it was cylindrical and wouldn't fit the footprint, nor was it short enough even if it had - in the end it was secured sideways with a glob of silicone to the chassis. The wires on it went to the appropriate place, and it's been working fine ever since.
The friend who wired it had a pretty good working knowledge of transformers - If it helps I can include a photo of the footprint, but I don't recall it having pin numbers marked on the PCB and the Cinemag likely has a different pinout than either of the above transformers.

 

[Harvey Birdman]

These transformers are designed for conditions where they are driven by a source with very low output impedance and with DC bias current. Also the output most likely needs to be terminated with a 600 ohm load to get the correct result. So it seems to me that your measurement results are wrong and not relevant (especially the bumps on LF and HF). You need to measure and compare them in real and identical working conditions, in BA283AV or similar circuits.

With respect... I think you're missing the point of the exercise.
The 2 xfmrs that were tested in reference to the Marinair are supposedly designed to duplicate or clone the the Marinair, so keeping that in mind, as long as they are fed with same signal level and impedance and the outputs are driving the same load, the results of the test should be the same.

"You need to measure and compare them in real and identical working conditions"
That is exactly what he did! He performed a real test and performed the identical test on each transformer. It does not matter that they were not driven by a low Z or had DC applied to them or were not hanging off the output of a BA283, they are transformers and if they are designed & manufactured to clone the performance of a Marinair, then that is what they should do. The test performed showed the difference between them.

Too often on these forums I see contributors going to a great deal of effort and spending a lot of time to provide us with information that is unavailable elsewhere only to find somebody telling them what they have provided is wrong and not relevant. We need to be more supportive.

I applaud Whoops for his effort and hope he isn't discouraged by any negative comments. The data he provided in just the first 3 posts is valuable to many of us and more than likely not available from the manufacturers.

Apologies if I've offended anybody.

 

[Whoops]

Thank you Harvey.

I'm one of the highest posters in this forum and also one of the members that has an highest reaction score. I don't get discouraged if someone corrects me or provides a different perspective on how to improve things. I take that opportunity to learn and improve my knowledge. We all give free advice and help, and we also learn for free, that's the deal, and I need to learn a lot in terms of audio electronics.
I'm a professional sound engineer (recording, mixing, mastering) and that's my area of expertise, I'm probably one of the most experienced people in this forum in that area but as far as audio electronics I'm limited, I do this as an hobby just for fun and what I learn I learned it here and it's great that more knowledgeable members chime and provide more info.

I believe what moamps wrote is correct and useful, and I think his intentions are good, I just completely disagree that the measurements are "not relevant", because like you and me said they were done with identical conditions, so not optimal like moamps advised but relevant nonetheless.
It would be great to do better and complete measurements, but I can't at the moment, and also I did at the time what I could do.

 

[kingkorg]

I'm way too late in this discussion. I've done the same thing shooting out stock transformers in Alctron 73 pres and comp 54 against Carnhil. They should be the same thing as Golden age.

The difference between the two were more obvious in distortion curve page of the REW. Don't know if you still have those measurements saved @Whoops . Anyways, the stock chinese performed "better" is a sense where it actually had lower distortion. You need to be carefull with gain structure so that you actually push output transformers without saturating the stuff in the front end. However i'm not sure if you want less THD in these. I kept both in the circuit, switching between the two via added switch. In practice i rarely use it, but why not have both for some variety.

As always great work mate!

https://groupdiy.com/threads/alctron-cp540-neve-2254-33609-clone.66698/