DIY Buffer?

[hilbi]

http://www.skrydstrup.com/dual%20buffer.htm



Does anyone know a good DIY project what will create something like this?

I did read some info on buffers on muzique.com and pete cornish his site

[Dirk_Hendrik]

Spec's

High impedance input.  
Unique RFI protection.
Low impedance output.
Transformer isolated Tuner Output.
Dimensions: 120 x 95 x 57mm (DxWxH)


Leaves me with questions:
1) Why the need for a transformer isolated tuner out>
2) Why is that thing so awfully big? (for a buffer that is)
3) Why is so extremely expensive (US$ 296 ). (c-mon! It's only a buffer!!)

[smashinator]

I loved this part.

Perfect when running long cables in hostile inviroment.

Like Chernobyl?  :lol:

Looks to like it's big in order to make room for a transformer.  The transformer is there because there's all this space that would just go to waste otherwise.  :shock:

It costs as much as it does for the same reason all the other boutique pedals do.  I'm sure making a buffer requires the same amount of work as making a booster.

[waldo041]

i recently cloned my unity gain buffer preamp and put it in a box much smaller and made a schem and a parts layout of the original. it originally goes in a guitar pre volume.  i also put in a schem and description of what it does inside a guitar. it is relatively the same in a stompbox only post volume. i was doing it for the peter cornish post on his buffer.but fits the bill i believe here also. so here it goes. it will stay as long as i can keep it online. do what you guys want with it. it is a great piece of gear and i believe a great tool for anyone who uses effects. peace and enjoy, waldo

unity gain buffer preamp:

PDF:
http://www.geocities.com/waldo041/unigainbuf.pdf

or

http://thehydrophonics.tripod.com/unigainbuf.pdf

[Paul Perry (Frostwave)]

The owner's manual (at the site) shows why someone (might) want two buffers in a box.
I can't personally think why anyone would want a transformer isolated tuner output, but if you do, there it is! Fortunately, for a tuner, the last thing you need is audiophile quality, so if you are duplicating it, get the cheapest 1:1 from Mouser that you can.

[niftydog]

Most buffers add high frequencies that don’t sound natural.

That's an astonishingly large pile of giraffe poo.

Anyone else looked at the Power Center?

6 x 9VAC outputs. Hmm, really handy! Plus;

All low voltage AC outputs uses 2.1mm barrel connectors.

Just so you can destroy your pedals with minimal confusion!

[bwanasonic]

I can't personally think why anyone would want a transformer isolated tuner output, but if you do, there it is!

Because the tuner can make funny noises thru your amp if it's not isolated . I use the *tuner out* on my Ernie Ball volume pedal and a Korg DT-1, and when the tuner is on, you can hear a faint noisy *fringe* on the notes. Not something I always notice on gigs, but for practicing and recording it can be annoying. Goes away when I shut the tuner off.

BTW- I love how people here will line up to shit on someone trying to make a living selling effects if they don't approve of their ad copy! Warms my heart :roll:

Kerry M

[Paul Perry (Frostwave)]

Because the tuner can make funny noises thru your amp if it's not isolated . I use the *tuner out* on my Ernie Ball volume pedal and a Korg DT-1, and when the tuner is on, you can hear a faint noisy *fringe* on the notes. Not something I always notice on gigs, but for practicing and recording it can be annoying. Goes away when I shut the tuner off.

BTW- I love how people here will line up to shit on someone trying to make a living selling effects if they don't approve of their ad copy! Warms my heart :roll:Kerry M

Thanks Kerry! I didn't imagine anyone would design a tuner that did that!
As for advertising copy, I personally don't have any problem with ad copy unless it is deliberately misleading, or a downright lie.

Looking at the advert in question, I see this:
"Most buffers add high frequencies that don’t sound natural. This is mostly the result of poor quality op-amps."
I don't quite know what to think of that..!?

[Connoisseur of Distortion]

bwanasonic, stop dissing on the vultures.

paul perry, stop pwning bwanasonic

seriously, let's all be friends  :lol:

[Dirk_Hendrik]

Because the tuner can make funny noises thru your amp if it's not isolated . I use the *tuner out* on my Ernie Ball volume pedal and a Korg DT-1, and when the tuner is on, you can hear a faint noisy *fringe* on the notes. Not something I always notice on gigs, but for practicing and recording it can be annoying. Goes away when I shut the tuner off.

BTW- I love how people here will line up to shit on someone trying to make a living selling effects if they don't approve of their ad copy! Warms my heart :roll:

Kerry M

OK, next question:
If that tuner would make funny noises, why wout a transformer take that away. If I'd take an opamp as a non inverting buffer I'd have a better isolation! As far as I remember that EB volume pedal is completely passive so there's no buffer isolation between amp and tuner out. Maybe
a resistor or two but not active buffering.

On your BTW:
I am always amazed that there's such a little people daring to look at a design from a critical perspective and express this critisism. ?

[Paul Perry (Frostwave)]

bwanasonic, stop dissing on the vultures.
paul perry, stop pwning bwanasonic
seriously, let's all be friends  :lol:

Well, I'll drink to that! I certainly wasn't wanting to pwn any1, i didn't even know what pwn meant :oops:
And I'd be the first to agree, that for isolation, a buffer should do, but maybe there are power supply considerations that lead people to want to isolate the box electrically from the tuner, God knows (remembering those big tube powered tuners).
Maybe the transformer is a step-up one, so you get a decent sized voltage signal for the tuner, plus anything fed back is correspondingly downsized.
Anyway I did learn something useful from the user's manual, which is why someone might want 2 buffers in 1 box. And I'm always happy when I learn.

[Duke of Metal]

There is the new "AMZ Super Buffer" on the http://www.muzique.com/ that looks like it might be a nice buffer.

Check it out here:
http://www.muzique.com/lab/superbuff.htm


hope that helps,
Duke

[Satch12879]

Leaves me with questions:
1) Why the need for a transformer isolated tuner out
2) Why is that thing so awfully big? (for a buffer that is)
3) Why is so extremely expensive (US$ 296 ). (c-mon! It's only a buffer!!)

I've got answers:

1) Yes for the reason that was mentioned, tuners can do nastiness to your signal if split passively (see my signature).  The Korg rack tuners are notorious for this particularly with regard to ground looping and noise working its way back into the signal.  Also, the transformer provides ground isolation so that output can be used as a splitter to a second amp or signal path (you know like parallel effects routing, which I know it's a strange concepts for most pedal snobs...) to avoid ground loops or ground differential problems.  

2) Yes for the transformer and because some people don't like cramming itsy-bitsy, little wires in their boxes connected to microscopic PCBs with components mounted on their sides and all kindsa nonsense.  I've placed my single buffer in a 1590-C box which is 120x94x53mm (versus a 1590-B at 112x60x27mm) so I have room to move, solder, and house the small size, RS prototype pad-per-hole board confortably.  Eventually I want to use a Bulgin pedal drawer and this enclosure has the width and depth I need.  Furthermore, that's the Dual Buffer which has two independent signal paths, therefore two PCBs necessitating the large size.

3) One, shipping costs from Denmark to North America; two, high quality audio transformers like the ones Jensen or Lehle make are very expensive, even in large quantities (like $70+ for single units); three, rule of thumb, take production costs and multiply by 3 (? correct me guys) or so for retail cost.  Hell, Pete Cornish's Line Driver is close to twice what this costs.

Valid points, but you gotta remember that DIY Stompbox cats are a different beast than the clientele Skrydstrup markets to.  Most just don't think that way it seems because their situations don't necessitate them to.

Steen Skrydstrup along with Mario Marino at Axess-Electronics are the real deal and I defy anyone (save R.G. :mrgreen:) to design and build some of the stuff he manufactures.  I mean when was the last time Bob Bradshaw or Mike Fuller returned an email, on time and in person?

As for the opamp harshness nonsense, it's really a red herring.  There are some chEEEAp opamps being used in commercial gear, just because of the phenomenon of low-cost in large numbers making sense.  If you are a large, assembly line manufacturer, you aren't going to handpick parts because you don't have time or manpower to.  As for the nasty frequencies, some cookbook buffer designs I've seen let in a HUGE range waay above and below audio.  If you aren't careful with your part selection and detailing, you will get lots of crap.  It's just like John Suhr replied to me in a thread over at Huge Racks, Inc. that even though buffer circuits are simple in concept, the options you have to tweak them are really limitless.

[bwanasonic]

Just to clarify - my rant was at the general turn these threads take. The best criticisms of a device you think is overpriced and of questionable design, is to:

A: Not buy it
B: Design a better one and sell it cheaper.

I have the utmost respect and admiration for guys like Paul Perry who have put their money where their mouth is. If this Skrydstrup guy is selling poorly designed overpriced crap, he won't be around too long. If you really want to discuss the guy's design and pricing, invite him to the forum with an email. ...And when he doesn't respond to your email in 10 minutes, THEN you can stab him in the back!
:shock:  :lol:

Kerry M