[Vitalstatistix]

I recently purchased a MG Head OTL from Nick at Audio Valve Active (Sydney, Australia) and I cannot be happier.Let me say first and foremost that I don't have any interests, pecuniary or otherwise, in the man or his shop. I'm just a very happy and satisfied customer.

Nick is an ex-experimental scientist at the CSIRO in ultrasonics and he still consults there casually. So he knows his stuff! He is the sole ASL dealer in Australia and a very good one too! He has a showroom for those who would like a demo.

Recently I raised the issue about the negative feedback not working properly. Nick resolved the issue in 1 day and also provided some neat upgrades as compensation. Now the amp sounds so much better!

For those who are looking for ASL products (Twin Tubes anyone?) or looking to upgrade their MG Heads, look no further than Nick at this address:

Quote:

Audio Valve Active, 1 Raleigh Crescent, St Ives, NSW Mobile: 0403 491 523 Shop: 9746 6190

 

[enak]

How much did it cost?

 

[braillediver]

-

 

[Vitalstatistix]

The MG Head OTL costs $650 AUD.

He upgraded the capacitors and power supply for me. Widened the soundstage and improved details are immediately obvios.

 

[braillediver]

'

 

[taoster]

Quote:

Originally posted by Vitalstatistix The MG Head OTL costs $650 AUD. He upgraded the capacitors and power supply for me. Widened the soundstage and improved details are immediately obvios.

Glad youre a happy camper! nothing better than a retailer turning a negative situation in to a positive experience!

now, its tube rolling time

the spending never ends.

 

[N@Z]

Quote:

Originally posted by braillediver I picked up 2 Raytheon 5751’s with Black Plates and Windmill getters from: http://home.att.net/~chimeraone/tubelist5751.html For 16 beans US each. Used sure but they sound nice. I’m looking into tweaking the MG Head but it’s tight in there. I was going to do the volume pot shunt with a 47K resistors first. There’s a thread in the DIY section.

I took this off the website, what's the difference? Besides price & description that is.

5751 JAN Raytheon Special Triple Mica Black Plate with D shaped Top Getter Halo
5751 JAN Raytheon Red Label Double Mica Black Plates with Cross shaped Top Getter Halo
5751 JAN Raytheon Yellow Label Double Mica Gray Plates with U shaped Top Getter Halo

Sorry but I'm a n00b user to the MG Head. These are for the left & right tubes right?

 

[braillediver]

.

 

[Wodgy]

Quote:

Originally posted by braillediver The 5751 is the middle tube, the signal tube. Originally it is a 12AX7; the 5751 is a military version of the 12AX7.

Just to clarify, 5751 is not the same tube type as the 12AX7. (One is not the military version of the other.) The 5751 is a lower-mu tube than the 12AX7, with only 70% of the gain of the 12AX7.

Fortunately, they tend to be interchangeable in most preamp circuits, including the MG Head.

 

[braillediver]

YMMV

 

[N@Z]

Thanks for the explaination.

Does that mean that the 12AU7, 12AT7 or equivalent can be able used on the MG Head?

I get it now, the two left & right tubes are the EL84, what others can be used here?

 

[Wodgy]

Quote:

Originally posted by N@Z Does that mean that the 12AU7, 12AT7 or equivalent can be able used on the MG Head?

The 12AU7 can be used in the MG Head. 12AU7's have even less gain than the 5751 -- only 30% of the gain of the 12AX7, but don't let this dissuade you! Some 12AU7's sound very, very good, especially out of the OTL output.

I don't believe the 12AT7 can be used in the MG Head.

You can find valid substitutions for the 12AX7 and EL84 at:
http://www.nostalgiaair.org/NostalgiaAir/otcr.htm

 

[N@Z]

Thanks again Wodgy. That URL is really useful.