[avahifi]

For all of you using an Ultra preamp, Ultra DAC, T8 preamp and/or T8 DAC (only those with 6N1P tubes installed) here is a very nice nearly free do-it-yourself upgrade:

Step one:  Replace the 6N1P tubes only with 6CG7 tubes.       We like the EH brand from New Sensor.

Step two:  Notice that now the cover will not fit because the 6CG7 tubes are slightly taller.   

Step three:  The easy fix is to order some 3/8" x 6-32 male-female spacers from Digi-Key, their part number 8400K-ND. Screw these into the top of the chassis six cover screw locations.  Place cover on top, and fasten with the 6 4-40 x 1/4" cover screws.  This will raise the cover enough to clear the new tubes. Not elegant, but it works.

Step three, the much harder fix (for the preamplifiers only):  Remove circuit board, remove 6N1P tube sockets, replace with (shorter) original Cinch type sockets (still available as NOS from several sources).  Replace 1/2" spacers holding board to chassis with 1/4" spacers.  This lowers the circuit board and the tube sockets enough so the cover will fit as originally.

Step four:  Enjoy the sound and smile.

Regards.

Frank Van Alstine

P.S.  We don't plan on doing this in production because there is not enough appropriate low profile tube sockets available to use for a production run.

[martyo]

Thanks Frank.   aa   

[oneinthepipe]

Thanks, Frank.

I will try this with my T8+ DAC and T8 preamp (which will be delivered today!).

What were your impressions with the different tubes?

[robinje]

So, adding spacers under the top would result in the side cover screws not lining up with the chassis holes, correct?   

[oneinthepipe]

Digi-Key has, for me anyway, a minimum order.  Maybe I will just leave the top covers off.

[sts9fan]

oneinthepipe: "You Do It Electronics" may have these.  I have also seen them at Home Depot

[mmurt]

http://www.newsensor.com/ProductHighLight.aspx?ProId=103

This is the tube, yes?

[Wayner]

I guess that's the one.

W

[rcag_ils]

$37.12 each? I think I'll pass.

[oneinthepipe]

http://www.newsensor.com/ProductHighLight.aspx?ProId=103

This is the tube, yes?

There is also the standard version EH 6CG7 for 25.00 from New Sensor. 

There are NOS tubes for 11.00 and up here:   http://www.audiotubes.com/audtube.htm

I am waiting to hear back from Jim McShane before I buy any tubes.

[oneinthepipe]

$37.12 each? I think I'll pass.

The same tubes are available as a matched pair for 44.00 here:

http://www.boiaudioworks.com/6CG7EHGoldMatchedPair

[oneinthepipe]

oneinthepipe: "You Do It Electronics" may have these.  I have also seen them at Home Depot

I will stop buy YDI tomorrow.  I am too exhausted to make the 3.7 mile drive to YDI tonight.  Playing with my T8 preamp that was delivered today has tired me out. 

[tgp06]

OITP-Likely a min order at Digikey because they come in a bag of 10. A bag is about $4.00-$4.50, IIRC.

Try Triode Electronics for the 6CG7s.  EH for $11.75 ea, various NOS for $16.95 ea...no additional charge for matching.

[oneinthepipe]

OITP-Likely a min order at Digikey because they come in a bag of 10. A bag is about $4.00-$4.50, IIRC.

Try Triode Electronics for the 6CG7s.  EH for $11.75 ea, various NOS for $16.95 ea...no additional charge for matching.

Even when I tried to put 10 bags in the cart, I got a minimum order error.

Thank you for the tube info.  I am going to stick with Jim McShane for tubes.  He knows tubes.  He knows all about tubes.  He knows the electrical, electronic, construction, and sonic aspects.   He can spot a mislabeled tube.  He is a tube encyclopedia.  His prices are as good as anyone.

[tgp06]

OITP-Call Digi-Key on that old-fashioned device known as the telephone if you keep getting a minimum order error. I ordered a couple bags of 1/4", 3/8" and 3/4" from them about two weeks ago(via phone). Only cited Triode as another possible source- I have no affiliation with them other than as an occassional customer.

[martyo]

I like Triode, I go to their "bricks and morter" location, cool place to just look around at all the vintage stuff they have.

[tgp06]

I've tried the spacer idea on some components with black faceplates and covers before-the bare aluminum spacers stand out.Painting them flat black makes them virtually disappear,which greatly enhances the asthetics.Use a zinc chromate primer or acid etch prior to the black topcoat.You can spray all at once by screwing them together and putting a 4-40 screw in one end and a nut on the other.

[turkey]

I've tried the spacer idea on some components with black faceplates and covers before-the bare aluminum spacers stand out.Painting them flat black makes them virtually disappear,which greatly enhances the asthetics.Use a zinc chromate primer or acid etch prior to the black topcoat.You can spray all at once by screwing them together and putting a 4-40 screw in one end and a nut on the other.

You could probably also get a piece of 3/8" wide brass or plastic or whatever and paint it black, then cover the entire front gap between chassis and cover with it. It looks like K & S engineering has an appropriate size of brass stock, so your local hobby shop is a good place to start.

[martyo]

Heading into the city to Triode after work.........

[avahifi]

Slight mistake in my first notice herein.

The spacer has 4-40 threads, not 6-32.

Regards,

Frank