Building a 45 SET

[kevinkr]

Originally Posted by mltube

Just another possible brain fart of mine, How about an srpp 6sl7 in first then a 6ah4 driver for the 45 output? Just throwing some ideas around, what do you think? Could be very transparent.
I have many of the 6ah4, 6bl7, 6bx7's on hand also that I wasn't thinking about at the time of starting this thread.


Found a NOS Mullard GZ34 for rectification...!

A 6SL7 SRPP running at 2mA will drive a 45 to full power very nicely. I think you loose something when you add unneeded stages...

[mltube]

The James Mod. JS-6113HS opt came today.
Awaiting other components for some tube porn here.
Then Assembly will commense
I must admit these transformers are sweet looking.

[kevinkr]

Originally Posted by mltube

The James Mod. JS-6113HS opt came today.
Awaiting other components for some tube porn here.
Then Assembly will commense
I must admit these transformers are sweet looking.

I think you will find the James to be quite nice..

[mltube]

Happy day, the pair of James JS 5-200's arrived today!!
This is a nice pair matched in size and shape to the opt's.
I am separating the power supply with filtering to each chanell, just for overkill.

Now awaiting a special ordered potted power tranfo from hammond model 370DXP, should arrive 1st or second week of Aug.
This build is a little extravagent, but I always wanted one this nice, and building these ourselves creates a product that will be passed on.

Now for the signal caps, I have a lot of black spragues that sound really nice in circuit, but if you were building a one off special unit what would you use in terms of sound quality and reliability?

I am waiting on chassis choice once everything has come togather, just to make sure everything fits. (I am looking at the new wood sided hammonds)
I like the full wood wrap ones, but the have a new chassis that has wood enplates that I am leaning toward 10"X17"X3" .

Pic's will be published here when all components have arrived. I promise the drool factor will be here...

Have a great DIY day!!!

[kevinkr]

Originally Posted by mltube

Happy day, the pair of James JS 5-200's arrived today!!

<snip>
Now for the signal caps, I have a lot of black spragues that sound really nice in circuit, but if you were building a one off special unit what would you use in terms of sound quality and reliability?

<snip>

Have a great DIY day!!!

My choice (all teflon) in order of preference would be:

• Vcap
• REL TFT
• Ex Soviet FT3 Teflon

All save the Russian Teflon are costly, but as you need only a couple I'd go for it. My choice is the Vcap despite its high price, I just haven't heard a less colored, more transparent cap than this.. All that said the other two choices will be very good as well.. Try to stick to values of 0.1uF or so for cost and capacitor HF performance.

[mltube]

I am building this 45SET with overkill in mind.
It started as a simple project, but escalated with my DIY mind.
Looking for your personal suggestions for filter and signal caps.
I won't say money is no object here, but if there is enough proof of mfg quality and sound quality it will be on order.

On a different note, drifting off cap subject....

My budjet has been blown out the door so far, but its for an audio amp right!
The 45's were a little spendy also but they are NOS Kenrads and measure as a very close match on my Simpson tester. They are in the 90% range with perfect getter flashing. Not gassy at all. They look brand new even though over 70yrs old.
For the vol control I have very nice set of NOS AllenBradley 100k MONO's (hot molded carbon with carbon wiper pad). (very quiet contol)
I was looking at a step vol control, but the AB's have been a mainsay on my bench, and have never sounded bad.
The 27's remain as input, for now, because along with the solid plate RCA's that I have, I bought a very nice pair of globes 227's Mesh plate RCA radiotron's that measure very similarly. I have high hopes, and I know I will have them working flawlessly in the end.
Excitement building....

Have a great day
Michael

[mltube]

Thanks Kevin,
I will give the russian teflon's a try.
I have read enough of your posts and value your opinion.
Price is really not an issue anymore, as this is being built for overkill now..
Thanks again for your input.
Michael

[mltube]

Kevin,
I have 3 crates full of NOS US military oil in paper metal can caps that I nearly forgot about.
They range from .25uF600v- 8uF1000v. Many sizes to choose from
Have you used these? I have been holding them for special projects, but they slipped my mind. My basement is a virtual warehouse of goodies...
Michael

[mltube]

Purchased capacitor samples...
Russian FT-3 .1 600v teflons
Solen .1 630v
Clarity Cap ESA .1 630v
and
Clarity Cap 2.2mF 630v snubbers

I couldn't decide, so I'll try a few versions.
They will get used with this project or the next anyway.

I also found many Sprague Black Beauty's in a box and along the way found a large batch of Sprague Bumble Bees .005, .011, .022, .05, .12, .15 and .5 in 400 and 600v. Nice basement find, I must have bought them years ago.

Suprising what you find when you clean out the storage area.
Have a good day
Michael

[mltube]

Scored another pair of 45's ST Raytheons $40 and they match closely

Also I have been looking at a pair of Sophia mesh plate globes for a future trial,
but I will wait on those when project is completed.

Happy day to all
Michael