building paraglow 45s

[rockdoc]

I have spare chokes, power and Cobalt (!) output transformers , and C4S kits I bought when I built my paraglow 45 amps in (how can it be that long ago?!...) 2001. Time to put this stuff to work.....  Any ideas of what I might change from the original schematic? Unbelievable amps, by the way. I was running the Avantgarde duos and what music! I'm going to play around building some efficient speakers this winter; the Duos, as amazing as they were, are 12,000 miles away now.....

Steve T

[Paul Joppa]

Two thoughts:

1) There was a change in power transformer, which changed the operating points a bit. That, combined with the variability of power line voltage, means the operating points can be off optimum. Can't say anything more until we see voltages.

2) At one time, John Tucker offered an upgrade to shunt-regulate the driver; this was sometimes called "Paraglow II". The Paramount soft-start upgrade is similar and currently available. There are plusses and minuses to both.

[howardnair]

hello steve---good to see your name--are you still on the cape--I am still on the island --I am beginning to think I received a life sentence--ahhh building speakers is always fun--I cant think how many I have built--several of the first ones made a lovely bonfire
my favorite so far are something called a Jericho horn--I curved the insides-and wrapped the birch ply in Cypress and mahogany-there are so many designs out there it is hard to pick one --howie

[rockdoc]

My last build was the Lowther Medallions. Sold them rather than making a bonfire though......

[rockdoc]

I might need to order some EXO-46 nickle transformers; my current speakers are Zu Soul Superflys, 100 db efficient but 16 ohm, and the Cobalt EXO-45s I have are 8 ohm transformers.

[tsingle999]

I would try your cobalts first. Ive run 16 ohm speakers on the 8 ohm taps and have preferred that sometimes.
Anyways the best world would be to try both transformers and keep the ones you like and sell the ones you don't like as much.

[Paul Birkeland]

I might need to order some EXO-46 nickle transformers; my current speakers are Zu Soul Superflys, 100 db efficient but 16 ohm, and the Cobalt EXO-45s I have are 8 ohm transformers.

If they truly are 100dB, having the ability to switch between 8 and 16 Ohms can become very handy, especially with an amplifier like the Paraglow that is AC heated. 

[rockdoc]

Being able to switch would be nice, but the parafeed transformers from magnequest are either 8 or 16. I'll order up the EXO-46s in nickel, 16 ohm, and swap them in to the amps I have.

The Zu's do sound good with the 8 ohm 45 amps I have, but of course, the speakers being optimized for 16 ohms, I'll have to try it.

Steve T

[rockdoc]

Can anyone tell me what differences I would hear between nickel and pinstripe EXO- 46 output transformers for the 45 paraglows?

I'm going to sub in the cobalt EXO-45s I have as well, and see how they sound.

Steve T

[Paul Joppa]

Sounds like you will shortly be in a good position to answer that question.

Seriously, these subjective reactions are so easily influenced that's it's much more valuable (educational) to  minimize expectations before you listen. I look forward to your report!