30904 attenuator works!

**Elitopus1** · November 28th, 2016, 03:13 PM

Did you know Ashly built amps that look like this?

They're MOSFET too.

What?!?

I did not know that

**bowtie427ss** · November 28th, 2016, 03:20 PM

They appear on ebay now and then. I don't think they were made in large numbers. But, they are out there, we've even discussed them here briefly.

**Elitopus1** · November 28th, 2016, 04:27 PM

So how are the Ashly powerflex amps compared to the FET or FTX series? I know those two series are good but have no experience with the powerflex. Those are either 4 or 6 channels?

Or I should say are there any Ashly mosfet amps I should avoid?

**Petro** · November 28th, 2016, 05:00 PM

Congrats Bill glad it worked out !!!!!

**BillWojo** · November 28th, 2016, 05:39 PM

Bowtie, I was not aware of the part about the spider shims. Is there some other way I can do this? I do have Mylar shim stock from 0.0005 to 0.030 thickness in sheet form. Maybe I could make one? I was thinking that it was as easy as the small format drivers.

BillWojo

**BillWojo** · November 28th, 2016, 05:53 PM

Just got off the phone with Bill at GPA. He is going to send me one in the mail. He also said that it can be centered with a 200Hz test tone and after centering to do a sweep to see if it sounds ok.
Can anybody suggest a good frequency generator for an android?
Thanks

BillWojo

**Elitopus1** · November 28th, 2016, 05:57 PM

I didn't realize there was any difference between replacing a small and large format diaphragm either. So you have to center it?

**bowtie427ss** · November 28th, 2016, 06:04 PM

Originally Posted by BillWojo

Bowtie, I was not aware of the part about the spider shims. Is there some other way I can do this? I do have Mylar shim stock from 0.0005 to 0.030 thickness in sheet form. Maybe I could make one? I was thinking that it was as easy as the small format drivers.

BillWojo

I don't know what the appropriate thickness is, most important that the shim isn't too thick such that the assembly gets stuck on the pole. A quick call to Bill at GPA would be definitive.

You could try just plopping one in, if it buzzes, you'll have to loosen the locating dowels and shim it. Take your time, you're working with eggshells and a 30lb hunk of iron.

- - - Updated - - -

Originally Posted by Elitopus1

I didn't realize there was any difference between replacing a small and large format diaphragm either. So you have to center it?

Must be you didn't get the memo.

http://www.greatplainsaudio.com/LgDrvrDiaRepl.pdf

The locating pins on lg format drivers are not fixed. They allow you to remove and replace the same diaphragm in situ. But, they do not allow interchangeability like the guide pins on the small format drivers.

**Elitopus1** · November 28th, 2016, 06:19 PM

Ah I was wondering why the guide pins have phillips head screws. That makes sense!

Guess I'll have to do the same thing when I get my new GPA diaphragms

**bowtie427ss** · November 28th, 2016, 05:40 PM

Originally Posted by Elitopus1

So how are the Ashly powerflex amps compared to the FET or FTX series? I know those two series are good but have no experience with the powerflex. Those are either 4 or 6 channels?

Or I should say are there any Ashly mosfet amps I should avoid?

I have absolutely no experience with these amps whatsoever.

I just want one.