Buffers. I need a buffer. I have questions about buffers.

Beef

Evening all,

Sorry in advance I write a lot.

So buffers are probably the most boring purchase I can fathom, closely followed by tuner pedals, but unfortunately I think I "need" one to fix a problem with my amp.

Backstory w/ amp for anyone interested by curious electronic problems, otherwise skip ahead: copped a sweet '78 Fender Champ for criminal cash on gumtree. Sounds amazing... except for the fact that every single true bypass pedal I have will POP really loudly when I turn them on/off, unless they run into a buffered pedal. I actually just picked it up from JPF amps on Denmark St, who said that he couldn't find anything wrong with the amp. He explained what he thought the problem was but it went over my head somewhat, have emailed him hoping to get a written explanation for a dunce like me as I'd love to understand it. High impedance... DC voltage leakage... I don't know. They're obviously extremely knowledgable and seemed dead sure the amp was fine, and while I'm extremely ignorant, I'm still fairly certain it has to be the amp. Or at the very least some sort of specific and bizarre incompatibility between this amp and true bypass pedals, even if it's ostensibly fine.

There's absolutely no pop whatsoever when I plug into my Roland JC50, and the pop is present but virtually imperceptible going into my Harmony H400C, which is way older than the Champ. I tried isolating each and every pedal on my board just now, and every single true bypass pedal popped really loudly when it was just guitar, pedal and amp. The only ones that didn't were my Flint (when in buffered mode) and the DD-7. 

So basically, assuming there is nothing obvious to fix on my amp (which is actually strangely disappointing as it turned out to be a £50 diagnosis for it being perfectly fine - which is both very reassuring and pretty frustrating) then the only fix is to keep a buffered pedal at the end of my chain. Which eliminates all pop completely. Only thing is I defo want my looper last in my chain. The only pedals I'd want after it would be some kind of 'always on' boost type thing or perhaps a reverb, neither of which I have buffered versions of. Would rather not tbh. 

SO, my questions:

1. Sadly, I think I need a dedicated buffer. Does anyone have any recommendations? I know they're dead simple little things, but the sheer price discrepancy amongst certain brands is mad and makes me wonder if there's more to them than I'm imagining. There's a Bright Onion one for £30, a gorgeous little Visual Sound one for £50, TC Electronic £55, Analogman £70, Suhr £100... It's madness. Surely they can't be too different? I just need one with a small footprint that won't colour my sound unnecessarily. 

2. Not opposed to making my own, I'm learning but I don't know enough about electronics yet to source all my own parts. If anyone has a recommended kit then hit me up. Frank at JPF recommended I get a very specific op-amp if I make my own, but I can't remember it. Any idea what it might have been? 

3. Buffer placement. I know they're supposed to go first thing in your signal chain, would there be any negative effects on my tone by keeping a buffer last? Similarly I want to replace my Polytune, which is first in my chain, with a buffered tuner like the Boss Tu-3 (genuinely gassing for that overpriced Waza TU-3... what the heck is wrong with me) - would there be any positive or negative effects from sandwiching all my pedals between two buffers? Currently the DD-7 is the first buffer in my chain which is the 6th pedal in. Tone sounds good, but I wonder if there's a whole new dimension of frequencies that I've been ignoring by not placing a buffer 

Bless you if you read all that. Hope one of you electronics buffs (haha!!!) can help me out. Cheers.

ICBM

Why not just keep the DD-7 at the end of the chain? It does looping as well as delay, and if you want to use a dedicated looper as well you generally want to delay the loop rather than loop the delay or you end up with chaotic out-of-time repeats. (Unless that's what you want, of course… )

You probably don't need a buffer earlier in the chain if your patch cables are short and high quality.

If it's definitely a DC leakage problem from the amp you could in fact have the amp modified very simply with a large blocking cap at the input to prevent any DC reaching the pedals.

octatonic

Surely you need a beefer.

Beef

I already have that cowvered man @octatonic

@ICBM thanks man, it's a good call. But I tried having the DD-7 last for a few days before I took it in for a diagnosis. I agree its often better to delay the loop, but it's currently the only delay on my board, so it felt too limiting to have it last and not being able to play with delay without it affecting whatevers looping. 

All my patch cables are short and decent quality, that's good to know. I'll stop lusting after the TU-3w. But a dedicated buffer is still needed for the end I think.

Re. modding the amp. That'd actually solve everything I imagine, but it feels a bit wrong to mod a pristine vintage amp, even if it has issues. Just a bit baffled by it all to be honest. I don't doubt they had a thorough look at it, but I don't really get how there can be popping like this with any and every true bypass pedal without their being some sort of issue. Does every 70s Fender Champ also have this problem then? Seems unlikely.

ICBM

The issue is that vintage valve amps were designed before pedals became commonplace, so no attention was paid to DC-decoupling the inputs - many modern amps are now done that way exactly for this reason. It's not really a 'mod', anyway - on a hardwired amp like a Fender it's entirely reversible and non-destructive. You just need one cap and one resistor added to the circuit. It's certainly not a 'mod' to replace electrolytic caps when they fail due to age, anyway.

Not all Fenders do it - it can be a problem caused by conductivity of the eyelet board, which varies from one example to another and is a pet hate of many amp techs because it can be a real pain to properly fix.

If you won't want to use the DD-7, try a Boss FRV-1 Fender Reverb - ideal with that amp .

Beef

That's very interesting, thank you man. Extremely helpful as always. I will look into the blocking cap mod, that does sound a heck of a lot less barbaric than I initially imagined. I would love to fully sort it out with a long term fix like that as opposed to just masking it, but perhaps a buffer pedal will suffice in the meantime. I've heard the buffers in Boss pedals are actually really good, so it does make a little more sense to get a pedal that would double as a buffer than just buying a boring old dedicated one (although finding space on the board is the ever-present obstacle) - will look into the FRV-1!

Sporky

The reason why there are so many buffers at so many prices is that the market demands them.

A good (in engineering terms) buffer can be made with about £15 of parts (at DIY prices) and sold for £30-40 with an appropriate cost for labour. It'll be quiet, clean and do exactly what a buffer should - unity gain, flat frequency response, DC isolation, high input impedance and low output impedance.

However, guitarists in general are an odd bunch, and want things like "CLASS A" in the marketing blurb. Or they don't like chips in the signal chain, so the complexity goes up, they start adding controls so you can make it be not-a-buffer and so on and so forth.

I'm reasonably confident the Bright Onion one is probably one of the most buffery buffers you can get, and the others will be increasingly not-actually-buffers. Incidentally, the Boss pedals aren't great buffers, they have less than unity gain. But they're easily good enough, and you get a pedal into the bargain.

As for position in the signal chain, standard approach is that the front of the chain and the end of the chain are probably the most sensible places to put the things, but really they should go where they're needed. In your application the end of the chain is where the good will be done.

crunchman

I always have a buffer early in my chain.  I have a Big Sky last which is buffered.  If you want an excuse to get a Big Sky then it is an awesome pedal.

I'm currently using a clone of a Cornish buffer.  If you interested in building your own then there is a kit here:

http://shop.pedalparts.co.uk/Cream_Buff_guitar_signal_buffer/p847124_8506552.aspx

I sourced the parts myself and built it on vero board and saved a fiver or so.  It's actually in a box with an MXR Microamp clone.

I haven't done a direct AB and it may be a psychological thing but I think it does sound a little better than the Boss one that I used to use (TU3).

The other option is to get a pedal like a Soul Food which is meant to have a decent buffer and doesn't have a huge footprint.

Sporky

crunchman said:

I haven't done a direct AB and it may be a psychological thing but I think it does sound a little better than the Boss one that I used to use (TU3).

It could be the teeny level loss in the Boss - small enough that you don't hear it as being quieter, just "not as good".

That's also a brilliant trick if you ever need to bias an audio shootout - make the thing you want to win about 0.2dB louder. That's usually just enough to swing the results.

Beef

Sporky and Crunchman thanks for your input! Much appreciated.

While I would bloody love a Big Sky, I'm woefully short on space at all times, even with a Pedaltrain Novo 24 - so I don't think it's an option unfortunately! Tried the next board up, but it was just way too large.

I'll check out the Cream buffer too, sounds cheap, easy and probably just what I'm looking for. 

And Sporky, I do just want a simple buffery buffer! No frills, but it needs to be decent! At this point I'm torn between a kit like the Cornish one, the Bright Onion one (have got a few of their pedals and they do great stuff) and the Visual Sound one purely because it's so incredibly small. Pretty sure anything else would be overkill for me - although I must admit I'm not exactly sure what the functional repercussions of buffers being "increasingly not-actually-buffers" are. You'd assume the opposite given some of their prices. 

Johnnyseven

Buy a Boss tuner and put it at the end of your pedal chain then there's no need to buy a buffer.

Beef

It's a good shout, I considered that. But then I assume you have to make sure all other pedals are switched off before you tune, which isn't ideal. 

Sporky

Beef said:

And Sporky, I do just want a simple buffery buffer! No frills, but it needs to be decent! At this point I'm torn between a kit like the Cornish one, the Bright Onion one (have got a few of their pedals and they do great stuff) and the Visual Sound one purely because it's so incredibly small. Pretty sure anything else would be overkill for me - although I must admit I'm not exactly sure what the functional repercussions of buffers being "increasingly not-actually-buffers" are. You'd assume the opposite given some of their prices. 

I think any of those three options will do you nicely, so my suggestion is go for the kit if you think you'll enjoy building it, the Visual Sound if its smallness is important, and the Bright Onion if neither of the other.

I think what happens with the not-actually-a-buffer stuff is that people try a buffer, and like what it does (increased sparkle is not uncommon), and think "this'd be even better if it could boost and have tone controls and make sandwiches". Boost and tone control and sandwiches are all good things, but they are not buffer things. Buffers can be made very well for not much money - even if you add in good power supply protection and such.

pj310

Tbh lack of sandwiches is a deal breaker for me both when it comes to women and buffers

Sassafras

If you want the absolute best, get a VHT Valvulator (sadly discontinued).
It's totally impractical for gigging because it's massive and heavy but for recording it's invaluable. It eliminates all hum, hiss and unpleasant noises and adds a lovely richness and complexity to your sound.
I know @Sporky will say that's not what a buffer is for but I don't care what he says when it works so well.
  

Sporky

The VHT Valvulator is an excellent buffer in the same way that the Space Shuttle is an excellent bicycle.

Sassafras

But it's one hell of a bicycle.

Sporky

Indeed. All those wheels and rockets and stuff!

ICBM

But despite its complexity and sophistication, the Space Shuttle is probably the most dangerous form of transport ever devised, by fatalities per journey, number of journeys, distance travelled, or any other standard measure.

Even more dangerous than riding a bicycle in London.

Johnnyseven

Beef said:

It's a good shout, I considered that. But then I assume you have to make sure all other pedals are switched off before you tune, which isn't ideal. 

How many pedals are you using that it's too much effect to turn then off, tune and then on again? Also how often do you need to tune, once at the beginning of a set is normally fine for me.

I run a tuner after my dirt pedals and it works fine.

ICBM

Tuners work fine after dirt, wah, compression, tremolo, delay (usually), and anything else that doesn't alter the pitch of the signal. Not sure about after phasing, I've never tried it.