MK-U47

[horvitz]

For us 115V people, I was looking at this one - the 263AX:

http://www.hammondmfg.com/263.htm

It has an extra 5V sec that wouldn't be doing anything, but it does make exactly 200V at 0.1A.

Maybe I'll take that 5V and hook it to a switch that toggles between "awesome" and "rad" and lights a light red or green accordingly. 

 

[Kingston]

2A "extra" 5V sec. That's a terrible waste of money and weight.

Also, this exact issue was discussed only two pages a go.

Sorry ioaudio for cluttering up your sales thread with transformer lore. I stop now.

 

[mad.ax]

You're absolutely right! Who need a stressed traffo? ;D I've edited my post...

The hipot test only verifies that the insulation of a product or component is sufficient to protect the operator from electrical shock. It is not warranty that the product is speced at 1500VDC!
But since safety agencies demands that 100% of the production to be tested, the hipot test have to be non destructive... So I can only HOPE that it would withstand 300V...
One would have to ask Triad Magnetics to get a definitive answer...
That said the C-7X is used in several tube amp PSUs without known issues... Bottlehead for instance. So I guess my hope is founded. Who would need a low voltage, 270 Ohms DCR choke?

Axel

 

[JW]

I'm definitely into getting in on the second batch. Couple questions.
Max, you've built this up and verified that that aren't any noise issues with running the two pentodes in parallel in the circuit?

Also, are the BV8's still being made from original laminations?

 

[rodabod]

Max, you've built this up and verified that that aren't any noise issues with running the two pentodes in parallel in the circuit?

It's very likely that these are two triode-strapped pentodes in parallel. Noise will likely be lower in this configuration.

Also, are the BV8's still being made from original laminations?

Max offers original laminations at additional cost if you contact him.

 

[dissonantstring]

hi max,
not sure if there is a list for the pre-order of the second batch, but i would like to get one set from the second batch.  my wife and i just had a baby a few months ago so i missed the first batch as i haven't had much time to check the forum lately.
thanks for developing this and letting us in on this very nice project.
cheers,
grant

 

[ioaudio]

hi all,

I am prepaired to have more kits in the future - but at the moment i cannot accept orders/payments until the first batch is shipped.
Pls check back in this thread for availability (use the notification feature).

After burn-in in the assembled mic the noise of the VF14r is comperable to the original tubes - like roddy stated noise is lower with the tubes running in //
Also the (dynamic) output impedance is affected in this configuration, resulting in the typical resonance behavior of the circuit near the lowest frequencies.
I will start a description&help thread while kits are shipping.

Most parts are in, but i have to wait for the costum made relais to show up next week.
Transfomer laminations are made from a costum treated Nickel alloy which i developed for the prior MK7 sets.
Only very few NOS laminations are left, keeping a stock for having a reference for testing/comparing.

100 coils make 50 transformers:

 

[Matthew Jacobs]

I just can't wait....

 

[Jim50hertz]

I just can't wait....

Uhuh... Just... Can't ...

 

[ioaudio]

shipping started today.
All paid kits will ship within the next days.*

thanks for your purchase!

-max

*edit: due to some time managment reasons shipping delays for one or two days. all kits should be out by the end of the week.

 

[tommypiper]

Where do we sign up for the next round?

 

[tskguy]

Yes how do I get in on the second round???

E

 

[madreza]

Yep interested for the second round !

 

[Davo]

+1 for second round, if you're makin a list

-d

 

[ioaudio]

All paid kits are shipping.

I´ll have a new batch, please check this thread for availability, no list.

thanks,

-max

 

[tardishead]

I want one of the second batch as well

 

[pedrocruz]

Depending on the price, im in for 2 (two).

Thanks

 

[wtmnmf]

Sign me up for two on the next round please

 

[TheGuitarist]

So does anyone know the sonic differences between the mk7 and mk47? Is it simply the mk47 will sound like a u47 and the mk7 will be u47ish?

 

[FerrariT]

So does anyone know the sonic differences between the mk7 and mk47? Is it simply the mk47 will sound like a u47 and the mk7 will be u47ish?

Since I own a mk7 kit and have been gone for a bit I was about to inquire of the same thing, curious of the "sound" difference between the two.

Actual it would be nice to hear some sound examples.