I've read somewhere that several of the coax leads can be replaced with a single conductor wire without introducing additional noise.  
Non HRM ODS BM 70 convert. Skyline TS  internal tube FX loop.
Which coax are some of you taking out for a straight wire?
Need to brighten things up a little, without the use of bright caps......you know, lose some of the conductor loss......
			
			
									
									Replacing shielded coax with single conductor question
Moderators: pompeiisneaks, Colossal
- guitardude57
 - Posts: 355
 - Joined: Fri May 15, 2009 6:19 pm
 - Location: Austin, TX
 - Contact:
 
Replacing shielded coax with single conductor question
Mike
I am never surprised and always amazed
						I am never surprised and always amazed
Re: Replacing shielded coax with single conductor question
Why not just use a bright cap?   I've been going through my amps and replacing the single stranded with co-ax as mentioned in other threads here.  Specifically, both connections between the OD drive and level pots, and both sides of the master.  Originally only the output sides were co-ax.  To my ears, it smooths the OD out a bit without killing the highs.   The amps were already plenty quiet with the unshielded wire, but I liked the co-ax better (very subtle, but audible).  Depends on the capacitance per foot of the co-ax, they are not all the same of course, maybe yours is higher capacitance.  Of course, it's always worth a try so you can hear for yourself.  If you want to remove the coax, start with the two inputs to the OD drive and OD level pots. 
Bill
			
			
									
									
						Bill
Re: Replacing shielded coax with single conductor question
Remember too, as Scott always points out, most amps that are used with a loop have a bright cap on the master, since you have an internal loop, it seems like the best starting point.  somewhere between 30pf and 50pf tuned to taste works for me...
			
			
									
									
						Re: Replacing shielded coax with single conductor question
If it only seems to lose the highs when the loop is used, try reducing the 220K/ 500pf resistor to 47k-100k.
This will allow more highs to the grid.
I also use a 47pf bright cap on the Master.
			
			
									
									This will allow more highs to the grid.
I also use a 47pf bright cap on the Master.
Tom
Don't let that smoke out!
						Don't let that smoke out!
Re: Replacing shielded coax with single conductor question
What is the concensus on the preferred type of coax to be use? I am using RG-174. Does anyone know the capacitance?
			
			
									
									**************************
Failure is not an option... it comes bundled with the kit.
						Failure is not an option... it comes bundled with the kit.
Re: Replacing shielded coax with single conductor question
Beldon RG-174 appears to be 30.8pf / ft.
That's very low.
The Beldon is copper plated steel on the middle conductor.
http://www.belden.com/pdfs/03Belden_Mas ... .67_71.pdf
That may part of my amps problem.
I like using the Teflon coax from Apex Jr. but somebody said it was rather high pf cable. Somewhere around 58pf.
I don't know but it may be worth trying some different cable.
I like the Teflon because it doesn't melt back when you solder it.
But I may need lower pf cable to cure some things about my amp.
			
			
									
									That's very low.
The Beldon is copper plated steel on the middle conductor.
http://www.belden.com/pdfs/03Belden_Mas ... .67_71.pdf
That may part of my amps problem.
I like using the Teflon coax from Apex Jr. but somebody said it was rather high pf cable. Somewhere around 58pf.
I don't know but it may be worth trying some different cable.
I like the Teflon because it doesn't melt back when you solder it.
But I may need lower pf cable to cure some things about my amp.
Tom
Don't let that smoke out!
						Don't let that smoke out!
- David Root
 - Posts: 3540
 - Joined: Fri Aug 04, 2006 3:00 pm
 - Location: Chilliwack BC
 
Re: Replacing shielded coax with single conductor question
I bought 25 ft of Brandon's shielded cable, a while back when he offered it. It is teflon insulation, white cover cable. Looks similar to Apex Jr. stuff I have but is slightly lower capacitance and 22 ga I think core. 
I'm using it in my current crammage, as they say, which is a 50W #13 approx Dumble ODS w/out reverb jn a Mojotone steel BFPR chassis.
Will be happy tp report on it when completed!
			
			
									
									
						I'm using it in my current crammage, as they say, which is a 50W #13 approx Dumble ODS w/out reverb jn a Mojotone steel BFPR chassis.
Will be happy tp report on it when completed!
- guitardude57
 - Posts: 355
 - Joined: Fri May 15, 2009 6:19 pm
 - Location: Austin, TX
 - Contact:
 
Re: Replacing shielded coax with single conductor question
Thanx
			
			
									
									Mike
I am never surprised and always amazed
						I am never surprised and always amazed