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Amp Guts Photos - Official Thread - Lets see those pics

Should we also add Bass Guts to this thread too?

  • Yes, Allow Bass guts, afterall Guts is Guts

    Votes: 223 28.7%

  • No way! Keep 'em seperate

    Votes: 553 71.3%
  • Total voters
    776
#1,322
12bass said:
The above reads like "my way or the highway"... not sure if that's what was intended... but it is certainly condescending and off-putting. FWIW, I've talked with other amp designers who understand the merits of a more minimalist design philosophy and recognize the differences in sound from using different op amps. Further, countless evidence-based audio manufactures have also recognized the merits of minimizing the number of op amps in their circuits and have used modern high performance op amps in place of more generic 70s designs, so it is not as if I'm suggesting anything "woo" here....
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Definitively. Simple and quick right to the point is usually the best. Using alot of opamp stages could eventually lead to more noise. could be More simple design issues and very basic circuits. Which can be done wrong when connecting so many stages. still relatively none issue or if swapping or rolling improves things. it just fixed crap circuit design. not the opamps fault

But then yes the need for all these "adjustable" features and " sweepable" features to make a product appear more high tech. uses countless op amp stages can be arguable if removing them makes it better or worse. just as arguable since such a high tech device requires the user a longer time span to get " familar" with the features. Meaning few days, weeks etc. to figure out the ideal settings where they just get left and parked anyways. Or people who have no clue and dial in pretty krap bass tone. A designer can do them a favor and put the controls where they cant make such horrid decisions lol

And yes the pretty generic curves most would dial in. Easily done with likely one or 2 opamps instead 8 to 12 or more. Arguments about keeping designs simple and low parts count agreed is better. Then again people will argue over the features in the first place. since obviously one design is " more advanced" but in the end is redundant and left in the same old places. Just 10 more things to adjust when the knobs get bumped in transport

Most amazing opamp suggestions are usually redundant. unless they offer more noise rejection. if you do basic sanity checks on most opamps to check if slew rate is high enough for whatever gain and bandwith being used in a Bass Amp. you realize just how minimal and low the requirements and plenty of " general purpose" opamps will match or exceed the rate neeeded by 2x or 3x.

Real issue is opamp topology with differential input topology. and main issue is related to Single Supply designs. and many times a high performance high precision opamp with magical opamp snob specifications. just goes to hell and is more noisy lol. than the good old turd TL0XX every day fet audio amps...

ive listened to hundreds of opamps, likewise enjoyed testing and playing around with majority of the designs my father did for Fairchild and National Semiconductor. With bass its just completely non audible. Only exception would be how much noise and hum is involved and that is mainly power supply design. other than that very basic understanding of gain and poor circuit values that can load down and cause very basic distortion. Rather obvious clipping or yes poor sound quality. If " opamp" swapping or rolling causes a audible difference. more than likely yes the " better" opamp just fixed a crap design. And the original opamp was fine. And agreed most the sponge or turd of a design is to many stages and poorly designed stages.
 
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#1,323
To put this absurdity in perspective, the Midas XL-3 which is one of the most respected boards in the pro audio touring world has over 20 TL-072 sections in each channel strip alone. This was a no compromise >$50k product using what their designer determined was the "right part for the job". Same goes for many Soundcraft, Allen & Heath and Yamaha products. Not just the TL-072 but it's closely related bipolar input cousins too.

"A part does not a console make" also applies to bass amps, there is so much more in the overall design that is 100 times as important IMO and IME. I'm allowed to say this because I don't just talk the talk as a hobbiest or enthusiast, but have very much walked the walk too, over a long career, with a verifiable lineage of products.
 
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#1,325
Some thread awhile ago someone was building some basic active preamp. used some ancient out production opamp.

simple solution i recommended the ever so classic TL071 72 74 etc etc.

oh boy here comes the snobs. one opinion is some old slow amazing opamp is whats so magical about the sound and you have to use that for a 2 band tone control.
or the other crowd has some amazing opamp that is gonna outperform it.

Exactly from basic practice amps to high dollar channel strips. Good old Texas Instruments

probably not any worse than guitar players paying 40 to 100 dollars for some old tube cause its so so amazing.
things sputtering and cracking and humming. yeah time change that tube dude....but but but but i paid 70 dollars for it.
mmmmkay
 
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#1,326
BogeyBass said:
Some thread awhile ago someone was building some basic active preamp. used some ancient out production opamp.

simple solution i recommended the ever so classic TL071 72 74 etc etc.

oh boy here comes the snobs. one opinion is some old slow amazing opamp is whats so magical about the sound and you have to use that for a 2 band tone control.
or the other crowd has some amazing opamp that is gonna outperform it.

Exactly from basic practice amps to high dollar channel strips. Good old Texas Instruments

probably not any worse than guitar players paying 40 to 100 dollars for some old tube cause its so so amazing.
things sputtering and cracking and humming. yeah time change that tube dude....but but but but i paid 70 dollars for it.
mmmmkay
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yes exactly same opinion with tubes... I build tube amps and circuit design is even more important than on opa or transistor design because less components.
I found classic Sovtek tubes more reliable, sounding better and quieter (on the heater) than expensive tubes someone gave me.
 
#1,327
agedhorse said:
Agreed in general. In particular, many designs in MI capitalize on the selective addition or generation or manipulation of harmonics, and how the op-amp behaves under these conditions is something that is considered an "off-sheet" application in the hi-fi audio world.

Then again, the audiophile hi-fi audio world that's so fond of digging into the minutiae also claims big differences in power cables and will spend hundreds or thousands of dollars for something that no double-blind test has ever shown a difference.

When designing a bass amp, parts are chosen for their particular behaviors and characteristics. Cost is an important characteristics, as is performance, reliability, stability.

This is the same type of argument used in point to point parts placement & wiring, turret boards, tag boards, etc. I use PCBs because it's the best, most repeatable, most consistent, most reliable method for my designs. The parts go exactly where I want them each time, the wiring is routed exactly where it needs to be each time, and it's easily repaired by
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Leo was right said:
Well I must admit, I am certified tech in audio, video and RF, now I am in audio and video fusionned dept, but for 30 years I was in audio.

Here is one of the best I heard, from a guy which is a very good tech: If you plug a speaker cable in a certain between the amp and the loudspeaker, and suddenly reverse it, it will not sound as good....

Or : IEC power cable under 500$ sound like crap.
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Sorry a word is missing: a certain way
 
#1,328
BoogieZK said:
yes exactly same opinion with tubes... I build tube amps and circuit design is even more important than on opa or transistor design because less components.
I found classic Sovtek tubes more reliable, sounding better and quieter (on the heater) than expensive tubes someone gave me.
Click to expand...
Circuits without global feedback are in general less forgiving of changes in component performance tolerances too.
 
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#1,331
Peavey Classic 60/60 Power Amplifier. Re-capped by me....

image1 (66).jpeg
 
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#1,338
Jeff Scott said:
I never understood the logic (?) of pumping the hot air from the heatsinks right into the rack that the amp is mounted inside of.
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In practice, it's not as big of a deal as you might think (for most amps). There are some exceptions of course.

Nowhere near as bad as the 10W resistor hanging in free air by its leads on that B-15N clone.

Did I mention how much I dislike point to point builds with parts just hanging there waiting to get damaged from vibration? Also, what a pain to troubleshoot and repair.
 
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#1,340
JB1962 said:
I agree. Its a mess. It was my first tube amp project. If I did it again, I would lay out everything nice on turret boards.
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You did a lot of good work on the B-15, right down to the cabinet, the faceplate, even the labelling inside the chassis. You obviously put a lot into it.

Lessons learnt always help with future projects. There were a lot of amps, still in service, built much like yours in the early days. Point to point layout is important and when done properly can produce a very low noise amp.

If you don’t need your amp to be road worthy, I wouldn’t worry about it. Otherwise, for starters, the power resistor can be mounted across a terminal board or on a custom made PCB.
 
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