Where to start for an exact accurate version of C800G

[Moby]

It's not about the ratio, it's about high headroom at the low end as it was suggested earlier multiple times. The one @Gus suggested might do the job.

No, bv8 isn't really an option, as Moby just said, the primary induction is crucial here.

Sowter 7490 maybe?
Pointing to amazing document by @ruffrecords

Exactly, but not just the headroom, levels from the tube will never reach the headroom limits of this kind of transformer.. Here we talk about the distortion of the signal and it affect the sonic of the microphone. The question is, do you want some transformer what can "pass the sound" or exact sound of the Sony C800G?

 

[Moby]

One more detail. I was not able to measure the laminations thickness but it's between 0.1-0.15mm. one more reason not to substitute this transformer with Bv.08, Bv.11 and similar. Those are using 0.35mm thick laminations. It change the sonics. Again... Anything between 7:1-10:1 will do the job but it will not sound the same.

 

[vmanj]

And if a transformer is made to order for me with close values of DCR and inductance and ratio, but the core will have a different size, will it be able to approach the C800G in sound?

 

[Moby]

And if a transformer is made to order for me with close values of DCR and inductance and ratio, but the core will have a different size, will it be able to approach the C800G in sound?

With a little luck, probably yes

 

[vmanj]

It's clear.

I have two options to order a transformer with such parameters from different masters.

One - on a regular core, but with a different size (probably larger) than the original.

The other is on a toroidal seat on a cobalt-amorphous alloy, but probably with a smaller size.
For my microphone body, this would be better.
But can (the same parameters) a toroidal transformer be no worse in sound than a transformer with a conventional core?

 

[gyraf]

For what the C800G sounds like - in my experience - it would probably make sense to go the route with a decent-sized amorph toroid, aiming for inductances like the original..

/Jakob E.

 

[Moby]

It's clear.

I have two options to order a transformer with such parameters from different masters.

One - on a regular core, but with a different size (probably larger) than the original.

The other is on a toroidal seat on a cobalt-amorphous alloy, but probably with a smaller size.
For my microphone body, this would be better.
But can (the same parameters) a toroidal transformer be no worse in sound than a transformer with a conventional core?

I really can't predict it. I can make it exactly as it is but minimum 50 pcs should be preordered to make it possible.

 

[vmanj]

I really can't predict it. I can make it exactly as it is but minimum 50 pcs should be preordered to make it possible.

Unfortunately, I can't order that many, I only need one..

Thank you so much for this information!!!

Excuse me, but have you measured the inductance of the second winding?

 

[Moby]

Unfortunately, I can't order that many, I only need one..

Thank you so much for this information!!!

Excuse me, but have you measured the inductance of the second winding?

I don't ask you to order I just give some info how it works. Nope, the sec inductance is the product of the ratio.

 

[vmanj]

I don't ask you to order I just give some info how it works. Nope, the sec inductance is the product of the ratio.

I understand

 

[kingkorg]

Unfortunately, I can't order that many, I only need one..

Thank you so much for this information!!!

Excuse me, but have you measured the inductance of the second winding?

That would put secondary at about 7.9H FWIW. What a monster!

 

[vmanj]

Thank you!

 

[Icantthinkofaname]

And if a transformer is made to order for me with close values of DCR and inductance and ratio, but the core will have a different size, will it be able to approach the C800G in sound?

Unfortunately, I can't order that many, I only need one..

Thank you so much for this information!!!

Excuse me, but have you measured the inductance of the second winding?

If you're getting some made to order you might want to try to set up a group buy. Even if some go unused I'm sure you could sell them on eBay. I'd definitely go in for a couple of them.

 

[Moby]

If you're getting some made to order you might want to try to set up a group buy. Even if some go unused I'm sure you could sell them on eBay. I'd definitely go in for a couple of them.

Group order is fine with me if someone wants to organise it. Of course that first batch goes with non profite price, as always

 

[vmanj]

If you're getting some made to order you might want to try to set up a group buy. Even if some go unused I'm sure you could sell them on eBay. I'd definitely go in for a couple of them.

I would love to do it, but unfortunately I can not, due to certain circumstances.
For this reason, I will look for "alternative" options.

 

[vmanj]

For what the C800G sounds like - in my experience - it would probably make sense to go the route with a decent-sized amorph toroid, aiming for inductances like the original..

/Jakob E.

I still have one version of such a transformer, in the form of a toroidal one on Cobalt Amorphous alloy.

With these characteristics:
DSR ~ 490/21 Ohm, inductance ~ 600H@50Hz, ratio 9:1.
The dimensions are quite small:
Diameter - 23mm
Height - 12mm

I'm only embarrassed by such a small size compared to a conventional core.
Maybe this will somehow reduce the bass response, etc. ?

 

[Moby]

I still have one version of such a transformer, in the form of a toroidal one on Cobalt Amorphous alloy.

With these characteristics:
DSR ~ 490/21 Ohm, inductance ~ 600H@50Hz, ratio 9:1.
The dimensions are quite small:
Diameter - 23mm
Height - 12mm

I'm only embarrassed by such a small size compared to a conventional core.
Maybe this will somehow reduce the bass response, etc. ?

Size can affect the headroom but in this case small sized core will do the job.

 

[gyraf]

yes, I agree - there's very small chances of overloading a 12mm stack of amorf by a microphone-level signal

so it's definitely worth trying

/Jakob E.

 

[vmanj]

Thanks to all.

The parameters of this transformer are slightly different from the values - 320/29 Ohm, 600H@50Hz, 8.7: 1;
against - 490/21 Ohm, 600H@50Hz, 9: 1.

Does it make sense to ask the master to bring the DCR parameters, ratios as close as possible to the original values, or is this difference insignificant and can be left with these values?

 

[Moby]

Thanks to all.

The parameters of this transformer are slightly different from the values - 320/29 Ohm, 600H@50Hz, 8.7: 1;
against - 490/21 Ohm, 600H@50Hz, 9: 1.

Does it make sense to ask the master to bring the DCR parameters, ratios as close as possible to the original values, or is this difference insignificant and can be left with these values?

It's close. But if he winds the custom one for you he can easily bring it to the spec's.