Pet Peeves

Schematics that have their primary signals flowing from right to left. For some reason this appears to be common in tube circuits for the B+ regulation. Why?

JDB.
[pettier than the Lockwasher Kops? You decide!]

I suppose it's an antique standard. It seems a little common in old stuff to find power flowing right to left and signal left to right.

Sure that's where they meet , i'm o.k. with that one

but WHO started gtr pedals going right to left with the 1/4 jacks ?

this one may need a poll as i would imagine quite a few pet peeves ,
but it'll probably out us guys who are spending less time building / using

[quote author="okgb"]
but WHO started gtr pedals going right to left with the 1/4 jacks ?
[/quote]


Yeah, screwing us lefties again. Great example of poor design. Buncha civil liberties stompin' assholes. Put'em parallel in the top, damnit.

the lack of decent left handed guitars at the store and never finding one that is in the middle not low end but not high end either.

I have 5 basses and not one of them is a leftie model.

> Schematics that have their primary signals flowing from right to left.

The only major deviant I have seen is early Mesa Boogie. I assumed their documentor was a right-left thinker. Or working directly from a prototype chassis. These are not formal drawings, probably done on butcher-paper. The early ones are not "designed", they were put together, played, tweaked, played, repeat until sufficiently smiley, and then copied for friends and markets. (BTW, most older M-B drawings have "errors", either oversights or deliberate copy-protection. Like missing bias resistors.)

Who else does it that way? Leo Fender's stuff was always rational (CBS Fender is sometimes tangled and swastika-ed). Marshall, Kay, HiWatt, Ampeg are "always" signal left-right as far as possible.

> common in tube circuits for the B+ regulation. Why?

> I suppose it's an antique standard. It seems a little common in old stuff to find power flowing right to left and signal left to right.

Well, you want signal left-right. In amplifiers, that usually means from small-signal on left to large-signal on right. And for passive filtering, it is cheapest to run many DC filter stages, and tap amplifier stages along the chain according to cleanliness needs and motorboating risk. So the raw power supply "should" flow from the raw DC for the large-signal stage on the right down to smoothed DC for small-signal stages on left.

When there is a single power-point for the whole contraption, active regulation and PSRR in each amplifier chip, then it makes conventional sense to draw the power supply left-right. But when the power points are A B C D E and applied to the amplifier stages E D C B A, it makes some sense to flow power right-left.

Some of the worst CBS-Fender plans try to draw an over-complex power supply both left-right and right-left.

Thinking about it I came to the same conclusion as PRR, that it reflects the successive filtering of a given supply as you move toward the input stages.

Also, to reinforce that, designers often produce schematics that to some extent map the physical layout onto the page. I rely on others for layout, and it's interesting how much influence the page layout has on the PCB, in the absence of any other specific input.

> designers often produce schematics that to some extent map the physical layout onto the page

Or versa visa. Somewhere I have a hand-drawn schematic with carbon paper taped to the back. I traced onto PCB, inked with Sharpie, etched, and built the schematic verbatim. With 3-pin devices, no topology is needed. My many-chip amp did need a re-draft of the schematic, to turn triangles into 8-DIPs, but using TL072 as stereo this is not a big puzzle.

OTOH, my Champ I copied Leo Fender's layout. When you have pots over there and sockets over here and small-parts on term-board in the middle, signal zig-zagging back and forth, it takes time to work out the "best" layout, and Leo built a lot more amps than I ever will.

[quote author="okgb"]but WHO started gtr pedals going right to left with the 1/4 jacks ?[/quote]

Maybe to match 'wrong' amps ? (inputs on the right) ? I never understood that either.




Bye,

Peter

[quote author="emrr"][quote author="okgb"]
but WHO started gtr pedals going right to left with the 1/4 jacks ?
[/quote]
Put'em parallel in the top, damnit.[/quote]
Right !

Look at for instance the Nobels-pedals. May perhaps be regarded as cheapish Boss-wannabes, but they have a few advantages over those Boss-ones:
indeed connections at the top AND a jack for remote FX-switching, which is great imho.

so right handed gtr players can plug them in with the gtr on.

[quote author="amorris"]so right handed gtr players can plug them in with the gtr on.[/quote]
Sounds like a reason and at the same time not so. I can plug stuff with either hand and I won't be special in that. Being right-handed, my left hand then even doesn't need to bother to lose the pick.


More wondering, amp-tone-controls with treble on the left-, bass on the righthand side...

> 'wrong' amps ? (inputs on the right) ? {early Marshall} I never understood that either.

That amp is "strongly based on" this amp. Except laid on its back, speaker cut off, tubes moved to the new top.



It is not an exact copy. Tubes, NFB margin, cap changes, and also Jim changed from the older knobs-on-top style to the in-your-face style. This also meant moving the tubes. With all those changes, in a 2-man shop, and customers hot to buy Fender sound without US-UK import costs, he kept the chassis knob-order rather than add time and errors to the production.

And when you pull the two chassis out and set them guts-up on the service bench, everything looks the same. Oh, every part is UK instead of US, tubes moved, but if you know the Fender then you know the Marshall. Nothing like trying to service a VOX.

[quote author="pucho812"]the lack of decent left handed guitars at the store and never finding one that is in the middle not low end but not high end either.[/quote]

My friend has gone through 15 years of hell on this one finding acoustic G's. Any suggestions in the under $1K?

My one big caveat is AC on the left. 70% manufacturers have it on the right, then why do a few insist on being different. Sorry dripelectonics :sad:

second, poor poly caps in gear I paid good money for.

third, the Demeter spring reverb I just recapped, pretty unfriendly to dismantle. Also, the filter caps were right next to the regs(which had no heatsinks, so the caps needed to be replaced sooner than expected.