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Glassware Aikido All-in-One (Octal) | ACF-2 Buffer
Glassware Aikido All-in-One (Octal) | ACF-2 Buffer
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Old 14th March 2019, 01:51 PM   #51
sunil is offline sunil  India
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Quote:
Originally Posted by kodabmx View Post
No, it must be LOG. I was being facetious...

50k should be fine. I use 100k as the middle ground. I used to use 1 MEG!
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Old 14th March 2019, 09:24 PM   #52
Wikkid is offline Wikkid  United States
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Originally Posted by sunil View Post
50K looks like the perfect middle ground.
Making the BEST choice nescessitates knowing to a certainty the impedance of the source and load... Especially the load.. Knowing total cable capacitance, and input capacitance of the load, is crucial, but it's rare that one does... In most cases, you'll wind up making a "best guess" at it, since knowing cable capacitance is something most don't.... and knowing the input capacitance of the load component usually requires manufacturer giving that knowledge... and they usually don't.

The consequence of getting this wrong.... is basically creating a filter... a Bandpass RC filter.. It will prematurely roll off either the highs or the lows... depending on whether you've chosen a higher or lower pot value....

Here is a very comprehensive thread on the subject: How to determine what value Pot (attenuator)???
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Old 15th March 2019, 04:06 AM   #53
alexcp is offline alexcp  United States
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Glassware Aikido All-in-One (Octal) | ACF-2 Buffer
Using a log pot between the input switch and the active circuitry as a volume control forces certain compromises. You know you're in trouble when you cannot fully control something "crucial" to performance, such as the cable capacitance when cables can easily be replaced. A better choice is to design the conditionality and compromises out of the volume control, as Baxandall did decades ago. Yet, the log pot tradition holds.

Last edited by alexcp; 15th March 2019 at 04:19 AM.
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Old 15th March 2019, 06:46 AM   #54
Wikkid is offline Wikkid  United States
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My solution is to just bypass the pot altogether and use an AVC!
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Old 16th March 2019, 01:32 AM   #55
kodabmx is offline kodabmx  Canada
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Glassware Aikido All-in-One (Octal) | ACF-2 Buffer
My solution is this:
I use one of these:Hi-End VOL / 2-Channel Relay Volume Control Board /Stereo volume board | eBay

I've tested it, and it's lowest Rin was about 1k or so. '

Here's the circuit:

I should say I've replaced the pot they give you with one of these... 1Pcs WXD3-13-2W 22K 220R Multiturn Trimming Potentiometer Variable Resistor | eBay
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File Type: png Aikidoesque-6N14P-6N6P-Volume-relays.png (31.5 KB, 196 views)

Last edited by kodabmx; 16th March 2019 at 01:36 AM.
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Old 17th March 2019, 01:47 AM   #56
alexcp is offline alexcp  United States
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Glassware Aikido All-in-One (Octal) | ACF-2 Buffer
Quote:
Originally Posted by kodabmx View Post
It seems it uses a pot plus ADC combination to control the relays. Do you experience the issue sometimes mentioned in connection with that arrangement, where the LSB of the ADC in certain pot positions is not stable and flickers between 0 and 1, so the respective relay keeps clicking even though the pot is not being turned?
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Old 17th March 2019, 03:11 AM   #57
kodabmx is offline kodabmx  Canada
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Glassware Aikido All-in-One (Octal) | ACF-2 Buffer
Once in a while but you just move the pot slightly.
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Old 23rd August 2019, 02:41 PM   #58
sunil is offline sunil  India
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Hi, the ACF-2 is done. Here's a pic of the cabinet that is w.i.p.

Is it fine to print John's name on the top plate ? Any problems with copyright ?
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Old 26th August 2019, 12:02 PM   #59
sunil is offline sunil  India
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Hi, the ACF-2 is done. Here's a pic of the cabinet that is w.i.p.

Is it fine to print John's name on the top plate ? Any problems with copyright ?
Please help answer.
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Old 26th August 2019, 09:51 PM   #60
kodabmx is offline kodabmx  Canada
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Glassware Aikido All-in-One (Octal) | ACF-2 Buffer
I can't answer that. I suggest you ask John Broskie (editor@tubecad.com) who created this kit.
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