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The ultimate dual 500 "rising from the ashes" build
- Thread starter grapplesaw
- Start date
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.
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
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
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.
So problem 1 is the input jacks are grounded to the chassis. They actually screw into the extrusion
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.
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.
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
I am really interested what you all think on these items so post away.
This unit has banana plugs ( one way only ) I personally like these as the plugs are tight and hard to pull out.
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
I am really interested what you all think on these items so post away.
Last edited:
- Joined
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- 74,757
- Location
- Gillette, Wyo.
- Tagline
- Halfbiass...Electron Herder and Backass Woof
- Joined
- Jan 14, 2011
- Messages
- 74,757
- Location
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- Tagline
- Halfbiass...Electron Herder and Backass Woof
Here is some on Ebay that look to be the same.
http://www.ebay.com/itm/6-Position-...404211?hash=item5d4aa6cdf3:g:n54AAOxykmZTMzXH
Also Antique Electronic supply
https://www.tubesandmore.com/products/P-0602H
- Joined
- Jan 14, 2011
- Messages
- 74,757
- Location
- Gillette, Wyo.
- Tagline
- Halfbiass...Electron Herder and Backass Woof
- Joined
- Jan 14, 2011
- Messages
- 74,757
- Location
- Gillette, Wyo.
- Tagline
- Halfbiass...Electron Herder and Backass Woof
- Joined
- Jan 14, 2011
- Messages
- 74,757
- Location
- Gillette, Wyo.
- Tagline
- Halfbiass...Electron Herder and Backass Woof
H H Smith No. 3006 6 Lug Terminal Strip
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
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
Last edited:
Joe,
Thanks for the heads up. Their price is bar far the lowest of them all!
Perhaps now is the time to stock up.
It appears that they are now selling them for 35 cents each. I don't know what their shipping costs are, however.
http://www.skycraftsurplus.com/phenolicterminalstripsolderable.aspx
Ed
Thanks for the heads up. Their price is bar far the lowest of them all!
Perhaps now is the time to stock up.
It appears that they are now selling them for 35 cents each. I don't know what their shipping costs are, however.
http://www.skycraftsurplus.com/phenolicterminalstripsolderable.aspx
Ed