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12b4, 6ca4 build questions....

kindof, im just thinking bout it right now..... do i want it in there... can i go off of the leds, or remove the led's and install light...
 
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i just got a parts express catalog, its kick a$$~
 
Alright, Its in, singin, humm in it. not bad.... can be drownded.. i let her run for a good half hour. Lil harsh on top end, maybe cause im not used to tubes. bass in there.... Im using a burned cd, so its prob that. but i love it! It's alive!

ask away!
 
How can i get rid of the hum, install the black things you sent bricktop? schematic? Thanks bolly, who i should really thank and praise is the three gents who made this posssible!
 
saltwater said:
How can i get rid of the hum, install the black things you sent bricktop? schematic?
Click to expand...

The hum could be from either: a) ground loop, b) power supply, or c) AC heaters.

to test for a) is any other equipment the 12b4 linestage connected to grounded? If your source is grounded or the power amp is grounded, you may have a ground loop.

Is the hum a buzzing or hissing sound or a low-frequency 60Hz thing?
 
nothing is grounded. i used a 3 in 1 power strip thing on the same outlet. (The house is old and no ground in the sockets) I plugged my power amp into it, cdp, and the preamp.. its a hum, when turned all the way down its there, till you get to oh 1/3 to 1/2 the volume, music covers it up. in no way is it static..
 
saltwater said:
nothing is grounded. i used a 3 in 1 power strip thing on the same outlet. (The house is old and no ground in the sockets) I plugged my power amp into it, cdp, and the preamp.. its a hum, when turned all the way down its there, till you get to oh 1/3 to 1/2 the volume, music covers it up. in no way is it static..
Click to expand...

There is a quick thing we can do to test if you need DC heaters. Do you have a 6Volt lawnmower or motorcycle battery around? A 12V car or sealed lead-acid can be used as well, but a little more rewiring will need to be done to test.
 
Welcome to the wonderful world of building your own Pre... 8 out of 9 will have some hum at first. :D

And you thought the hard part was the build out. Hah. :D :dunno:

Good luck and good on you. Congratulations. You were truly blessed to have some of the best teachers in the business. I've build a couple of Paks preamp designs. Talented bugger. :yes:

And Bricktop is something else too. Heck, anyone who quotes Kelly's Heroes has got to be good.... Us mear mortals can only aspire. :D

Keep us posted.
 
I got a car battery, but it's in the car. The kids wheeler is pull start, wonder if i have any lantern batteries... have to wait till the warden gets home... 5 ish....
 
no batteries.. i did some ccritical listening today. it sounds great on the top end of the spec. but the low end just aint there. i could see this for a bookshelf setup, but big no... is it the ccs, or do i need two fullrange speakers? just posting the stuff you prob curious about.. It does sound wonderful though
 
I'll post a DC supply schematic sometime soon for you to try. Should be a good thing to have anyway, even if there isn't any hum coupling between heater to cathode with the tubes you have in, that is not to say there won't be any coupling with future tubes.
 
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