The ultimate dual 500 "rising from the ashes" build

Why do you bypass the electro's on the driver boards Joe? not enough uf's ???
 
laatsch55 said:
Why do you bypass the electro's on the driver boards Joe? not enough uf's ???
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Hi Lee
Only bypass on the control board is the 2 on the OPA134 which is the manufacturer recommendation (Burr-Brown/TI) in order to achieve the GBW, stability and PSRR specs that they advertise.

The bypass on the backplane boards is to counteract the effect of chassis wiring inductance at higher frequencies and prevent resonances that potentially result from that .

Both are placed right at point of use where they do some good in the above regards. The same placed at the bulk caps would have no effect.
 
Gepetto said:
Hi Lee
Only bypass on the control board is the 2 on the OPA134 which is the manufacturer recommendation (Burr-Brown/TI) in order to achieve the GBW, stability and PSRR specs that they advertise.

The bypass on the backplane boards is to counteract the effect of chassis wiring inductance at higher frequencies and prevent resonances that potentially result from that .

Both are placed right at point of use where they do some good in the above regards. The same placed at the bulk caps would have no effect.
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Hi Joe. Thanks for the explanation on the bypass caps. There will be a new set of backplanes assembled for this project. This has completely different wiring path compared to any other I had seen. So must start off fresh. There are different placement location and number of ferric beads in the Quassi setup and different on right and left configuration. Will get your input on bypass cap lications after preliminary assembly put together.

Still trying to decide on using .33 or .39 emitter resistors


Any input is welcome
 
As a beginning we want to rework the ground system to start compliant.

So problem 1 is the input jacks are grounded to the chassis. They actually screw into the extrusion

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As the inputs will run through shielded cable to the volume pots and the back to the control board the now will be a double ground loop, once at the jack to chassis and an other at the ground of the control board . Not what we are used to in the 700 were the ground is isolated up to connecting the control board. One option is to drill out the heat sink and isolate the jack as per the 700. An other is except this additional ground as is. A third is to add a ground wire from the main ground on the power caps drect to the input jacks.


Time to send your ideas as contest closes one day or another.
 
While working on the heat sink with the input jacks it time to address in coming power. The old cord can be reused or the gram can be modified to a appliance inlet as pictured. This does keep the stock feature alive but may be all for the better.

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Last contest item today is what to do for the output jacks.

This unit has banana plugs ( one way only ) I personally like these as the plugs are tight and hard to pull out.

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I could replace them with the three binding posts from the 700 as used in later 5
D500. Or I can use some brass 30 amp ones I have. Only draw back to these is they are not plated

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I am really interested what you all think on these items so post away.
 
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laatsch55 said:
Do you have expandable bananas??
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Yes I have locking bananas for the 700 plugs, only way to keep them in.

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I have Emerson 108 15 amp plugs for my speaker cabinets

These are excellent plugs without the twist lock. The units installed are fitting the same ( holding power) but even heavier build on them

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grapplesaw said:
Last contest item today is what to do for the output jacks.

This unit has banana plugs ( one way only ) I personally like these as the plugs are tight and hard to pull out.

View attachment 23303

View attachment 23304

I could replace them with the three binding posts from the 700 as used in later 5
D500. Or I can use some brass 30 amp ones I have. Only draw back to these is they are not plated

View attachment 23305

I am really interested what you all think on these items so post away.
Click to expand...


I like the fatties....
 
The E-Bay offering looks like a direct replacement....
 
Mike went to the trouble of posting the link.......thy sure look like the ones though!!
 
H H Smith No. 3006 6 Lug Terminal Strip

grapplesaw said:
Hi anyone got # for these six pin terminal blocks??

View attachment 23309
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I am sorry for the delay in answering your post. I just got back from the east coast where I visited with some of my relatives over the holidays.
I also visited with Mark Weiss http://www.basspig.com. My brother-in-law and I had a great time discussing audio (as well as other things) with Mark and will be back in 2016.

The terminal strips were made by HH Smith now Abbatron HH Smith (632 Arch Street, Meadville, PA 16335)

http://www.farnell.com/datasheets/1927258.pdf

http://www.abbatron.com/uploads/pdf/SD-3000 SER.pdf

http://www.spectron.net/Abbatron - Catalog.pdf see page 29

Phase Linear also used their terminal strips, speaker binding posts, strain reliefs, etc.

You should find the price from their dealers (not from the guy on ebay who wants $22.97) to be less than half of what you see on ebay for the items noted in the previous posts.

Ed
 
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oldphaser said:
I am sorry for the delay in answering your post. I just got back from the east coast where I visited with some of my relatives over the holidays.
I also visited with Mark Weiss http://www.basspig.com. My brother-in-law and I had a great time discussing audio (as well as other things) with Mark and will be back in 2016.

The terminal strips were made by HH Smith now Abbatron HH Smith (632 Arch Street, Meadville, PA 16335)

http://www.farnell.com/datasheets/1927258.pdf

http://www.abbatron.com/uploads/pdf/SD-3000 SER.pdf

http://www.spectron.net/Abbatron - Catalog.pdf see page 29

Phase Linear also used their terminal strips, speaker binding posts, strain reliefs, etc.

You should find the price from their dealers (not from the guy on ebay who wants $22.97) to be less than half of what you see on ebay for the items noted in the previous posts.

Ed
Click to expand...

Skycraft had them at $7.95 for 10 of them which is an excellent deal.
 
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