PBC buffer discussion

middle_pickup

Well-Known Member

Just came across this video from Vertex Effects on the subject of buffers. Mason points out that too many buffers can have a detrimental effect on your tone. I'm interested to hear what you all are using for buffer settings on your PBC's, and if you have any other buffers outside of the PBC loops on your boards. I personally have a Goodwood Audio interfacer as the first and last thing in my pedal chain.

I've always left all three of the PBC's buffers enabled, and used the Goodwood buffers. Now I'm wondering if I might get a better result by flipping some of the PBC buffers off. I read in the manual that the line mixer and isolation transformer on the B output of the PBC need the latter buffers to work their best. I still wonder about the first PBC buffer though.

Anyone know how you can test the effects of a buffer on your tone other than by ear? I'm about to watch Wampler's video that Mason mentioned in this video to see if he has an objective testing method. Not dissatisfied with my tone, but if I can help the signal to noise ratio it's worth the effort.
 
I have the same setup with PBC/10 and the Goodwood Underfacer. I’ve tried with various combinations of buffers on/off and I don’t notice a difference (most likely because of the Underfacer’s buffers). I also leave them all on.

One thing to note is that the iso B won’t do anything on the PBC if your cable from the PBC’s Output B doesn’t go straight to an amp. Going to the Interfacer introduces ground back to the line, but since the Interfacer also has a ground lift on the second output you can just use that. Not really related to buffers but I thought it was worth pointing out for any who read this as that’s not common knowledge.

Interesting question about testing the buffers, I’m curious about this now too since I haven’t noticed a difference. Watching this post to see what others say.
 
With the requisite “I am not an expert on this at all” disclaimer…

I suppose you could use an audio frequency spectrum analyzer app (of which there are many, as I just discovered using google). If you wanted to make it really “objective”, play a note or two, or maybe a phrase into a looper, then play the looped phrase through your PBC, turning the buffers on and off and see what the frequency analysis shows. If there is an effect, I’d guess that there would be more high frequencies coming through with the buffers on, which may or may not be what you want.

As I often say, that’s free advice that’s probably worth what you paid for it.

My own experience is that having the first buffer on in front of any pedals going to the front of my amp seems to me to make my tone just perceptibly ice-picky. Or at least that’s how I perceive it. I’m not going through any buffer prior to the PBC input— just guitar cable, Temple Audio basic patchbay, then patch cable to the input. I’ve set all of my pedals in loops 1-6 in “fuzz” mode, so when any of them are on, the first PBC buffer is off. I work on the assumption that the signal level and impedance of my pedals in loops 1-6 work well enough with each other that the first buffer in the PBC doesn’t help. But buffers 2 and 3 are always on. And if I don’t have any pedals on in front of the amp, buffer 1 is on, and it sounds good to me.
 
I think Mason is a bit obsessed with buffer values, don't get me wrong he's very helpful and knowledgeable, I love the guy's videos and his willingness to share information but I've come to feel he's a bit obsessive when it comes to this topic. The PBC's buffer values if I recall correctly are 500Ohms and Mason feels at a minimum the input impedance should be 1 MOhm...Ron, believes differently; that throughout all the years of his experience 500 Ohms is just fine. I've not had any issues.
 
This whole thing has been a bit of a headache for me. I wrote this up last year, trying to explain my perspective:


I'm not modifying input impedance on anything anymore (i'm too busy as it is), but I'm happy to tell anyone how to do it if they really feel the need to try it.
Would never have thought to ask, and I definitely wouldn’t argue with anyone about impedance values, least of all you, Ron — I am utterly unqualified to do so!

My comments about how I set the buffers to make things sound good to me in my rig are very much A) completely subjective regarding what sounds “good” and B) totally specific to my rig. I tried out different combinations of settings until I found what works for me.

I’m just really happy that gear as good as all RJM stuff is exists and enables me to make noises I like
 
My comments about how I set the buffers to make things sound good to me in my rig are very much A) completely subjective regarding what sounds “good” and B) totally specific to my rig. I tried out different combinations of settings until I found what works for me.

That's definitely the best summary - everyone perceives this stuff differently, and what's a good answer for one person (and their rig) may not be a good answer for another.
 
After doing a little back and forth with the buffers I ultimately decided it isn't worth messing with. I notice very little difference when turning the buffers off in the PBC. My board has the goodwood interfacer as the first and last thing in the chain, so I'm always buffered anyway. There are obviously more effective means to tweak your sound. Thanks for the feedback, everyone.
 
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