It seems impossible to find out specs on amp parts

[catnine]

 Not long ago I posted asking whjat wattage a bias pot should be. I know I got mine from AES and emailed them and they said they would check and find out. It is a peavey part that is wire wound and 50kb and peavy told them when they asked about the watt rating that is was 50kb .

 I put in the peavey part number and one site had a list showing a similar looking pot , did not say whether it was wire wound and only a few had a watt rating of .2 watts. Based on that info this pot is 1/5 watt or perhaps better.

 It's just very frustrating . All I can find is that Alpha linear pots at 50k ohm are rated at 1/2 watt @500 VDC  and audio taper are at 1/4 @250VDC . The Piher 50kl trimmer that hoffman sells seems to be 1/4 watt at 250 VDC.

 I would think wire wound pots would be rated higher than carbon path pots.

 The part number Peavey offered AES was a pot with a switch and 31 detents . well my pot has no switch and only a center detent .
 Based on what PRR wrote " 35V^2/50,000 = 0.0245W  -- any pot will do"  All I know is I have -35 volts at the junction of the 220k ohm resistors . my ranger resistor is 10k ohm and the bias resistor is 26k in series with the 50kl pot I'm not really certain how many ohms the 35 volts is going through . I know to get the -35 volts I start with the pot full ccw and then turn it cw about half way so close to 56k .

 I don't know why I worry about this stuff , after all if the pot was crap then by three years time it would have failed and I also ran a pair of 6L6's with a GZ-34 through the same pot . nothing smoked . I guess I am trying to learn and it's a distraction and it bugs me to no end when I cannot find info on parts .

 I know the bias setting and mA draw of the tubes is based on the plate voltage. I recall I wanted to use either the 6V6's and 5Y3 or 6L6's and GZ-34 . I think I based this on a 5E3-A or webers 5E3P both used 6L6's and the 5E5 -A has the same plate voltage as my build with 6V6's and it requires about -35 volts . I have no idea what the plate voltage was when I used 6L6's in my build yet I could bias it proper.

 There you go , I am driving myself insane.

[sluckey]

You really don't have much to think about, do you.

There you go , I am driving myself insane. 

Finally, something we can agree on.

[PRR]

> I am driving myself insane.

You are as bad as Joseph The Carpenter studying the 2006 Building Code.

You NEED Joe's intuitive sense of load and size.

Roof beams, you need 6" to 10" logs. Shelf to keep the kid's incense and myrrh out of his reach, finger-thick. Don't need no stinkin' Code. Mostly don't need numbers.

Yeah, Joe could add the deadweight of adobe to the snow-load of Israel, allow 15% off for snow, then list all the available wood species in SS #1 #2 #3 Util grades, go into the BOCA span-tables... oh, and there's wind-load which could force 2x6 #2 even if the other loads are light.

Pot:

Joe might get fancy and think "50V is all I'll ever want. 50V/50K is 1mA. 50V times 1mA is 50mW or 0.050W. ALL available pots are higher rating. Therefore I will stop worrying about bias-pot power rating."

What if the Wise Men bring the kid some big transmitter tubes? A 1/4W 50K pot can take up to square-root of 0.25W*50K. SqRt of 12,500 is 111.8V.

What's wrong with Doug's trim pots?

[six el six]

What does 35^2/50,000 mean? Specifically what does ^ mean?

Well I answered my own question. It's 35 squared for those of you who want to know.

[Shrapnel]

What does 35^2/50,000 mean? Specifically what does ^ mean?

Most people do what is easy when they don't realize there is a ^{superscript option} available, or don't feel like typing out (without spaces) [ s u p ] and [ / s u p ] to surround the number of the power. So, they use an alternate and valid notation where ^ indicates raising to a power, and that power is the number immediately following it.

i.e.

2^2 = 2² =  4
2^3  = 2³ =  8

35^2/50,000 = 35²/50,000

[LooseChange]

I get the part about the roof beams. 

[catnine]

You really don't have much to think about, do you.

There you go , I am driving myself insane.  

Finally, something we can agree on.

 I happen to have plenty to think about . There is really no need to come on rude . I did say I'm driving myself insane as a joke and what does your comment really say to the 90 odd others who read this post. Just maybe one reader never thought about this one simple part and did use something that might fry. Or people read these posts just to see what the responses will be. I am not here to judge anyone. I came back here not long ago after being away for two years and asked a simple question and was told I must of slapped these amps together , judged right away. It was not until I posted photo's of the builds that I was accepted . From now on I will not ask another question.

[catnine]

> I am driving myself insane.

You are as bad as Joseph The Carpenter studying the 2006 Building Code.

You NEED Joe's intuitive sense of load and size.

Roof beams, you need 6" to 10" logs. Shelf to keep the kid's incense and myrrh out of his reach, finger-thick. Don't need no stinkin' Code. Mostly don't need numbers.

Yeah, Joe could add the deadweight of adobe to the snow-load of Israel, allow 15% off for snow, then list all the available wood species in SS #1 #2 #3 Util grades, go into the BOCA span-tables... oh, and there's wind-load which could force 2x6 #2 even if the other loads are light.

Pot:

Joe might get fancy and think "50V is all I'll ever want. 50V/50K is 1mA. 50V times 1mA is 50mW or 0.050W. ALL available pots are higher rating. Therefore I will stop worrying about bias-pot power rating."

What if the Wise Men bring the kid some big transmitter tubes? A 1/4W 50K pot can take up to square-root of 0.25W*50K. SqRt of 12,500 is 111.8V.

What's wrong with Doug's trim pots?

 Nice little story . I did not say there was anything wrong with the trim pot Doug sells , I needed one that I could adjust without removing the chassis, what's wrong with that ?

[sluckey]

I did say I'm driving myself insane as a joke

And I replied in kind.

[catnine]

You really don't have much to think about, do you.

I did say I'm driving myself insane as a joke

And I replied in kind.

 Really? It was the first thing you said , I fail to find the humor in that.

[sluckey]

I didn't see a smiley in your message either, but I knew you were joking. Maybe we're becoming to sensitive. It's easy to miss the intent sometimes when sitting behind a keyboard. Communications is not my major. You're not the first to notice. I'll try to do better.

[G._Hoffman]

You really don't have much to think about, do you.

I did say I'm driving myself insane as a joke

And I replied in kind.

 Really? It was the first thing you said , I fail to find the humor in that.

Dude, it's the internet.  EVERYTHING should be taken in the least offensive way, which is to say as a joke.


Gabriel

[catnine]

 I don't use smileys perhaps once . I was simply making fun of myself. Look I do realize my posts are long and packed full of all sorts of unneccessary info. I am wordy , that's just me . What I should have said was simply if anyone is selling parts to build an amp they have to source the parts so why not add in just the important specs? You can find resistor watt ratings and all sorts of info on caps . You can find a fender 10kL bias pot but why no wattage rating . It's there for PT's and OT's . One knows if they are building a certain amp or replacing a pot in an older amp they list what amps they are used in.

[sluckey]

...so why not add in just the important specs? You can find a fender 10kL bias pot but why no wattage rating .

BECAUSE IT AIN'T IMPORTANT! PRR and I have already calculated the power dissipated by a typical bias pot based on the numbers you presented. The power is so small that it ain't a factor worth considering. GET IT?


 

[catnine]

...so why not add in just the important specs? You can find a fender 10kL bias pot but why no wattage rating .

BECAUSE IT AIN'T IMPORTANT! PRR and I have already calculated the power dissipated by a typical bias pot based on the numbers you presented. The power is so small that it ain't a factor worth considering. GET IT?


 

 Yes I GET IT man . I wasn't asking again , I was saying my posts where to long and then said how I could have made the post much shorter and to the point. Now how would I have known if I had not asked . I am not good at math . I am not good with ohms law yet I can take a wiring diagram and even without a layout build an eyelet board and wire up a working amp . I can read schematics very well and compare them to decide what preamp section I can use with what power section . I can find the problem when an amp is not working . I worked on cars and trucks for over 35 years and could look at the customer complaint and then check the car out to verify the concern then look at the wiring diagram and just from that and a test to confirm it find the problem no matter what it was. They had what were called pin point tests that took you from point one to point 199 all tests based of being able to read wiring diagrams or not . I didn't use the pin point tests  whcih told you to substitue a good know componant , this would take weeks . Many times the wiring diagrams were wrong and I could find that as well and one reason specs are important to me is you cannot test something if the specs are not there. Case in point a power window motor switch burns out now if you don't know the actual current draw of the motor and you toss a new switch in and the motor works have you fixed it . So you are left with a choice get a new motor and see what it draws under load or take the chance and let it go with a new switch and if it comes back then justify to the customer why now they need to ;pay for a new motor and who pays for the second burnt out switch. I dealt with the techs and the ford engineers and the customers with fix it right the first time. That's why I still say specs matter.  

  I am pushing 63 and I do know what or what not to say . I know exactly how to push my wifes buttons but why would I want to do that. I was asking on some other amp forum about an issue and got back have you cleaned out your ears lately in referance to too much bright sound in one of my amps . This is something I would never say . Certainly I don't know anyone on any site personally there just is no way I would say something that I may think of as a joke having no idea what the person I am joking with is going to take it.

 I just want to learn a bit more so I can pay back the help I have got. and offer help when anyone needs it. I have tried. The internet is not like talking on the phone or in person so without that direct contact or at least a JK who can say what the mood or intent is.

[Cups]

I think we think alike catnine.I read posts that are borderline rude (even if the intent were not to be) and I ask myself "Is that necessary"
The difference is after being on forums so long it no longer bothers me. It's just a bi-product of communicating via forums.

[EL34]

I don't understand why you feel the intense need to know the wattage of common use pots
Pots don't flow any major currents and so it's not even an issue.

Resistors yes, pots no.

A rheostat is a pot that is used to flow major currents and you need to know the wattage rating on a Rheostat.

To me, it's like wanting to know what the ink on the jackets of wire, or the ink on resistors is made of.

Don't take it wrong, if you must know, you must know.
To each his own.

[Shrapnel]

It's very easy to miss intent, emotion, or humor on-line in a forum, email, instant message, or private message. It's very easy to miss all that when you receive a text message on a cell phone.

These smilies, emotes, or emoticons (you choose your favorite term) can help sometimes. It's easy to feathers ruffled when none were meant to be, and if you are like a duck with water sliding off it's back, you might even let intentional feather ruffling slide too without realizing. (THAT can be a good thing.)

I'm not going to pass judgment on anyone, Shoot, examine me and I'm sure you can find plenty of faults. They say to err is human, and to forgive is divine... and the doctors will say to forgive is to live longer... and they say it takes a computer to really foul things up.  Well, I think we got a computer foul.

[catnine]

I don't understand why you feel the intense need to know the wattage of common use pots
Pots don't flow any major currents and so it's not even an issue.

Resistors yes, pots no.

A rheostat is a pot that is used to flow major currents and you need to know the wattage rating on a Rheostat.

To me, it's like wanting to know what the ink on the jackets of wire, or the ink on resistors is made of.

Don't take it wrong, if you must know, you must know.
To each his own.

 I knew there was not much current going through this of any pot on an amp . At first I got the 50kL trim pot you offer but then I decided I wanted to be able to adjust it without removing the chassis so I got a pot and put it in. I had absolutely no idea if the pot I got was reliable , I just figured if the bias resister is rated at 1/4 watt then the pot should be close to the same. It's like the sovtek 5Y3 , you get one then find out later it's not a real 5Y3 and suddenly it becomes an issue for some not all. There is also a 5V4 which I got . I try to do research before asking questions , I punch in a tube or pot and all sorts of opinions pop up warning one don't use this or that and of course it's all internet forum based opinions , that tube shorts out , this tube rattles and so on.

 Bottom line is I came here to ask and got the answer . All I did in this post was express how frustrating it was to get info on parts. I can go to radio shack and get a trimmer yet who can say if it's junk or not. My intent was not to question the answers i got or some sort of quest for truth . What I did not expect was to get the responses I got in this post.  I get the impression this post was not even read just reacted to as if I rejected the info and help I got here. no it was the pot I got that I questioned .

[sluckey]

I get the impression this post was not even read just reacted to as if I rejected the info and help I got here. no it was the pot I got that I questioned .

Oh no. It was read. But you already had your answer before you even started this redundant thread. And that's what's so damn frustrating about your posts.

YOU DON'T LISTEN!

[catnine]

I get the impression this post was not even read just reacted to as if I rejected the info and help I got here. no it was the pot I got that I questioned .

Oh no. It was read. But you already had your answer before you even started this redundant thread. And that's what's so damn frustrating about your posts.

YOU DON'T LISTEN!

 I see how you can say I don't listen and this must be the part of the post that tells that .

"The part number Peavey offered AES was a pot with a switch and 31 detents . well my pot has no switch and only a center detent .
 Based on what PRR wrote " 35V^2/50,000 = 0.0245W  -- any pot will do"  All I know is I have -35 volts at the junction of the 220k ohm resistors . my ranger resistor is 10k ohm and the bias resistor is 26k in series with the 50kl pot I'm not really certain how many ohms the 35 volts is going through . I know to get the -35 volts I start with the pot full ccw and then turn it cw about half way so close to 56k ."

 I should have not posted at all , you are right . I did take your advise and PRR's advice. If I had not listened I would have dug through my box of pots and replaced the one in there I did not do that.

 Yes I post damned frustrating posts that seem to be somehow entertaining considering how many times this post was read. If they are so damed frustrating and my damn user name glares out then why even read them or respond to them . My second huge mistake was to even attempt to try and explain myself  Sluckey so you would not think I did not listen or respect your advice, I can clearly see I certainly failed there. There is not one damn question in my post . YES I GET IT!!!!!!  I go it the very first time I got the answer . My 3rd huge mistake was not trusting MYSELF , I chose the pot , I questioned the pot and for good reason in my lame mind . I needed a pot so instead of ordering one part I went to radio shack and they had an assortment of trimmer pots in a bag . I installed the one that looked like it was made the best and had a value I needed and guess what it smoked , not in this amp but one build from the same exact circuit , all I had to do was dial in the highest resistance and the pot would not hold the voltage then the wiper screw drive began to rock.
 I will NOT post another frustrating thing ( this reply is the last post of frustration) so let it be noted I realize this reply will fit the word frustating perfectly. No matter what anyone here may think of me one thing I can say is I have never been rude , never realized I was frustrating anyone and if that's deliberate that then I am then rude.

 

[sluckey]

Thanks.

[EL34]

I am not at the shop so I can't see one of the trim pots in person, but I believe it may be possible to insert a small screwdriver through a hole and adjust them externally.

They are very high quality trim pots, so it may be worth a try.

Just throwing out ideas, I have not done this but I have seen it done on lots of old gear.

[catnine]

I am not at the shop so I can't see one of the trim pots in person, but I believe it may be possible to insert a small screwdriver through a hole and adjust them externally.

They are very high quality trim pots, so it may be worth a try.

Just throwing out ideas, I have not done this but I have seen it done on lots of old gear.

 I did purchase one of your 50KL trim pots quite a while back and can't locate it  anywhere . If I recall the slote went through the trimmer. and it looked like a well sealed trimmer. On this build what I did was use a 5E3 black fiber type eyelet board which sets on three 1/2" tall nylon bushings and it also has a blank fiber board to provide insulation between the eyelets and the chassis held in place by machine screws and nuts. Then I built the bias board out of a left over section of the fiberglass board material you sell and mounted that on one nylon 1/2" tall bushing tapped the thick fiber board and used one machine screw to secure the bias board and I used your long eyelets . Trouble is for me anyway is I would have had to drill through all these boards to make an access hole which would have been over an inch away from the chassis hole . I think I used the trim pot you sell for another build which was a tweed style chassis and the bias board acess required only the removal of 4 screws to gain access to the trim pot. I even made the bias board for this build I have been talking about with three eyelets to match your trim pot legs then I thought about having to remove the chassis each time and decided then to use a small OD pot because there is not much room for a normal sized say Alpha pot and just drill one hole through the chassis and run short leads to the board. I do not want or intend to give anyone the impression that the trim pot you supply is by any means cheap stuff that was certainly not the case.

 If you are interested I built this amp out of a fried 71 fender music master bass amp and my first thought after going to the bare chassis was to get a PT that would fit and a eyelet board that would fit and then drill a hole for an extra 9 pin for the PI so in short it was sort of a tight fit and I started out with building a one vol one tone version of a 5E3 . Here are two photo's to show the board and full chassis. This was my very first attempt at building my own tube amp and of course I had to have a rect tube so I squeezed that in as well . But it started out as cathode biased and that is now where the bias board rests where the 10 watt bias resister and cap were. 10 watt bias resister because I could not decide if I wanted 6V6's or 6L6's and the sound of a fixed bias amp suited me better. I am not tech enough to place an arrow but you can see the bias pot right between the bias board and the PT and just below the gray fuse holder.

 Now if I had known then what I learned later and did do on another build. I built my own eyelet board using your parts and built it smaller , the fiber eyelet board I got from weber worked out with sprague caps yet the resisters were just long enough to make the reach so the next build I used your board and F&T filter caps and built the bias board right on the eyelet board . I used a blank black hammond chassis which was really smaller this this chassis marked and drilled using uni-bits and built a tweed style chassis.