"breadboarding" amps?

[toomanyslurpees]

I like to build stuff, but once it's built I'm horrible at getting the tinkering done, when I've built something and tried to make it pretty I have a hard time wanting to touch it. Do any of you ever build up an amp in a very temporary fashion for ease of swapping out components to find the something that's just right? If so, by what means?

[DummyLoad]

http://i2.photobucket.com/albums/y11/pmitchel/DSC01362.gif

http://i2.photobucket.com/albums/y11/pmitchel/2010-12-13_21-13-17_420.jpg

buttery and i have a LOT of fun... 

[overtone]

I do it just like DummyLoad, but I dare not show you a photo of how mine looks like!
It saves time when I try out my own ideas. Then you really can have much fun trying out your options.
By using connection blocks with the same pitch as the Keystone tag-strips I am physically checking my layout too, before drilling any holes. That is really useful, even though I do my layouts in CAD first, nothing beats seeing it for real.

[jeff]

 Cool. But I wouldn't play guitar in front of it. What happens when you break a string and it goes flying into it?

[RicharD]

>What happens when you break a string and it goes flying into it?

Good point.  First off, I use D'Addario strings which just don't fly apart.  They seem to be the only strings which can survive my gorilla hands.  They last and they stay in tune.  I still think Slinky's sound and play the best but they just don't last.  Here is a picture of my bread board.  You will notice the power supply is in back.  I prototype everything this way so as to keep the most lethal parts somewhat out of reach.  We also know not to lean in and make adjustments while holding a geetar.  I am an electrical contractor by trade so grounding posture is 2nd nature to me, still I also know that when you get too comfortable is when an accident can happen.  I'd be telling a lie if I said I've never gotten bit by the Zilla board, but I've never actually been hit hard fooling around with it (knocks on wood).  The last time I got the peepee knocked out of me was from a split chassis Silvertone.  It has a Molex connector that carries power and a RCA connector that carries signal and the only ground.  I had forgotten to plug in the RCA and did it hot while holding a guitar, a mistake I won't make again.  The last big scare was when one of my kittens jumped up on my bench.  I now make sure they are not in the lab when I'm messing around. This is a dangerous pass time we share.  It's always good to discuss safety precautions.  The only shoes I own are insulated work boots and my eye glasses are plastic lens safety rated.  The best advice I have is something I tell all my employees:

If you're not 100% comfortable doing something, then don't do it. 



My protoboard has 3 power supplies in it's belly.  6.3VAC @ 8A, 12.6VAC @ 4A, and 0 - 140VAC @ 5A via a Variac with an output voltage meter and current meter.  I can roll down the HT leaving filaments hot while I make changes.  As dummyload (formerly ISOTone) says, it's a lot of fun.  I can change a pot in 30 seconds.  I can build a Champ from scratch in about 30 minutes. 

[jeff]

 That is just so freakin cool. Are those screw strips from Radio Shack? I was thinking of doing something like this and I think you've inspired me to do so.

[supro66]

those 4 big blue batteries 

look like the ones we would start our 049 model airplane engines with

[DummyLoad]

allied electronics has a nice selection. it is difficult to find them with wire clamp screws - most have a binding screw which is made for a single solid (or tinned) wire looped around the screw shank. the wire clamp screw has a free-wheeling flat washer that can clamp down several wires of similar gauge.

the part for the # for the wire clamp screws is 515-0073 - link below has a pic. they are kind of pricey, but overall, it's easier to buy the screws than try to source the barrier strips with wire clamp screws. buttery found the last box of 50 count .325" 30 pos. w/ wire clamp screws in the US. at first tyco did not want to sell such a small quantity direct, but buttery somehow convinced them to do so.

https://www.alliedelec.com/search/searchresults.aspx?N=0&Ntk=Primary&Ntt=515-0073

use DIN mount octal relay sockets for octal tubes (duh!) and 7 pin tubes. use 11 pin DIN mount relay sockets for 9 pin tubes - this is the fast track. in version 2 of buttery's, i designed the PCBs that you see that hold the sockets. i never finished mine - it took us two days to machine buttery's on my sloooow CNC machine and i lost interest in the plan after playing with the .325" spacing barriers strips - use .375" spacing parts - they are longer but multiple wire connections are more manageable. did i mention that don't like the .325" spacing barrier strips? not at all. if you want the PCB artwork send either of us a PM.

be careful! my protozilla has only bitten me once, but admittedly i was doing something foolhardy to begin with. i have both version 1 models in my lab, after buttery and i machined version 2 for him, his original was gathering dust in his garage and i couldn't bare to see it unused. buttery built the cabinets for both version 1 boards - he did a beautiful job.  

we have hashed out a version 3 of the board that uses a simpler mounting method for the PCBs' (not as complex to machine), it is longer to accommodate .375 spacing strips with more tie points, it has a universal mounting plan for X mount type transformers (Z mount is PT mounting type you see in fender BF and SF amps) and it is larger (20" x 36"). it will likely be machined by a 3rd party.

you could build something similar with the .25" spacing radio shack strips on a piece of lumber on the fly on the cheap - most decent electrical supply houses sell the DIN rail and DIN mount relay sockets. some supply houses even sell the barrier strips, however, most seem to only carry the .437" spacing items.

[DummyLoad]

those 4 big blue batteries 

look like the ones we would start our 049 model airplane engines with

those are 680uF 450VDC computer grade electrolytics... i guess you could call them batteries! 

[Geezer]

I see the "chick" flowered screwdriver still survives.......nobody's gonna steal that one! 

[RicharD]

I love that screwdriver. 

>did i mention that don't like the .325" spacing barrier strips?

I'm OK with the barrier strips but the PCB mount ones are the suck.  They aren't aging well at all.  I expect any of them to fail at any time.

[RicharD]

Here are some other breadboard ideas.  Heinz has a very cool rig too, but I couldn't find the pictures.

[Ritchie200]

I love that screwdriver. 

Hah!  I remember that too!  How long have you had that?

I've got several boxes with post terminals.  Crude, but I can leave my old reliables connected up and swap them in and out.  I will post pics one of these days....
Jim

[RicharD]

My business partner gave that to me several years ago.  I used to have a matching box cutter but I lost it at work.  That screwdriver doesn't leave the bench.  Believe it or not, it actually has decent tips.  I just replaced my work screwdrivers.  Easily as refreshing as new guitar strings.

[supro66]

those 4 big blue batteries 

look like the ones we would start our 049 model airplane engines with

those are 680uF 450VDC computer grade electrolytics... i guess you could call them batteries! 

you are right

The ones I remember were red [ RAY-O-VAC ] 1 1/2 volt dry cell to light the glow plugs and cut our fingers on the props 

[toomanyslurpees]

Thanks for the insight, I was a little worried it was a dumb question but this is very helpful!

[andrew_k]

I designed mine primarily off the tubelab modular design, but was greatly inspired by the pair DummyLoad & Buttery built. I like that I can quickly wire up little sections while looking after my baby daughter then take them out to the workshop to plug in when I get a chance.

Here's one channel of a 6BM8 (triode-strapped pentode) SE "hifi" I'm building:

Ignore the pine plank with the PSU on it, that's my stand-alone PT test jig.

There's a solid core ground bus running the length of the board along with two lots of twisted pairs (10A each) for AC heater supplies.  On the shelf behind the board is an 8A variac, a 450VDC@275mA heavily filtered supply and 6.3VDC@3A along with function generators, and scopes which I use with this breadboard.

I spent a long time deciding on the size of the breadboard, what features to build into it and which ones to leave external (eg: no inbuilt variac etc), but now that it's built and I've used it for a couple of different circuits I'm VERY happy to have built it. Experimentation rules.  :hello2:

[DummyLoad]

I expect any of them to fail at any time.

solder wick and solder pullit are your friends...  i have spare strips.

--DL

[supro66]

I expect any of them to fail at any time.

 solder pullit are your friends...  i have spare strips.

--DL

I hear they suck 

[Tone Junkie]

Man guys thats inspiring Ive got to get me one of those. Im looking at parts as we speak by the time I get done with most of my builds Ive soldered and resoldered so much stuff,Im amazed they still work.
 I really like the moduler idea I do most of my soldering in the living room as my wife calls it the ugly corner, (LOL)
I could wire up the modules and I could have little modules of my fave power sections.  PI and pre amps
Then the sky is the limit buy the time I stick it in chassis it wont look like crap from taking it apart so many times. My wife wants to no why it takes me two months to build an amp. she doesnt realize i look at every one as a learning experiance and want to try all my ideas on each one.
This would be so much faster, Sorry Im preaching to the choir again, can someone say to much caffeine this morning.     
Thanks Bill

[Tone Junkie]

anybody found a cheap place to get the barrier strips rat schack was like $6.00 apiece I love the variac feature you guys are using. Thanks Bill

[Tone Junkie]

sorry guys allied has everything i need you pointed that out several posts back.
thanks Bill

[DummyLoad]

sorry guys allied has everything i need you pointed that out several posts back.
thanks Bill

use the .437" spacing barrier strips. the wire clamp screws allied sells don't work w/ .375" spacing barrier strips.

--DL

[Tone Junkie]

Thanks Dummyload its hard to call you that and realize Ive been talking to you as ISOTONE for a while. I will keep that in mind when i buy mine, those things are not cheap that big set up you guys have must have cost you a $150.00 just for the barrier strips.<G>. Do you think those chinese variacs at $60.00 bucks for 3 amp unit would work.
Thanks Bill

[DummyLoad]

...chinese variacs at $60.00 bucks for 3 amp unit would work?

yes, but the real question is for how long?  i really have a hard time trusting of anything that comes out of china that isn't distributed by a well known manufacturer - even then i have doubts. i am convinced that most of what china does produce is pure garbage.

i spec'd staco for ours. if you have the cash, that's what i'd recommend. price has risen about $30.00 since we purchased ours.

an AC ammeter is a nice addition - a 5A F.S. meter would do well.

yes, barrier strips were expensive - IIRC buttery paid around $400USD to populate 2 boards of version 2 protozilla - he bought the barrier strips - i bought the .25" aluminum plate material and paid for the PCB work.

--DL 



 

[Tone Junkie]

I feel the same way about chinese stuff my thought was to get one up and working and replace the chinese crap with better as I go. Thanks Bill

[1blueheron]

Sorry for resurrecting a zombie thread but the tube breadboarding intrigues me a great deal.  When I salvage the organs the tone generators typically are somewhat modular chassis.  Each 1 has from 3-5 tube sockets.  I am thinking it would be useful to use a couple set up fro octal base tubes and one for noval tubes and make a breadboard.  I have a couple transformers.  1 is 6.3 v if I recall of several amp capacity that I could use for the heaters.  I also have a bunch of screw barrier strips salvaged out of a telco switch and a lot of standoffs.  Besides a PT for the HT, what else would I need and is there a way this can easily be used as a tube tester?  I am running across some tubes locally that if they are good, they are a good deal but no way to verify if they are good.  Mostly garage sale/basement type stuff that people have no idea what its worth, but obviously I don't either if I have no way to verify it works.

If I can set up a breadboard tester, that would be great, if I need to buy an actual tester, what one is recommended and won't cost me a small fortune?

[Willabe]

Look in this link that Dummyload started today. In his 1st post he has pictures of his new bread board. 

http://el34world.com/Forum/index.php?topic=24259.msg260533#msg260533

A member, Silvergun, had a thread on building his bread board. I think I posted my bread board in there too?

Here's the link to Silvergun's breadboard thread;

http://el34world.com/Forum/index.php?topic=15445.msg148808#msg148808

And here's Sivergun's 'Son of a breadboard' thread;

http://el34world.com/Forum/index.php?topic=16551.msg163203#msg163203 

And here's the link to 'My breadboard'. I got my ideas for it from Dummyload and Silvergun.

http://el34world.com/Forum/index.php?topic=18354.msg187427#msg187427

[1blueheron]

Thanks Willabe.  I will dig into those links.