Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

HiFi (Chifi) tube amp build - but my own design.
#54

Hey all! I've been pretty quiet on this one because I'd been having some "mystery" problems, which really left me scratching my head. Amp 2 would work great, then it wouldn't, then it would, then it wouldn't. I've been testing different tube types, taking measurements, trying different voltages, having problems with red plating on different tubes, oscillations, then even having problems with sometimes one of the tubes not lighting up! I finally found the cuplrit(s). The octal tube sockets are junk! Usually if a socket is bad, you can move the tube around and get it to work or not work. Not in this case. I did have an occasional static in amp 1 and could move one of the tubes (same sockets) and get it to kinda quit. Figured it was a cold solder or something. It really came to a head when I stuck a "nice" set of 6V6's in there, and couldn't get things to sound right. Bass was weird, mids were scratchy - then they weren't, oscillations, low power ... things I wrote off as bad/weak tubes! Then I noted that only 1 6V6 was that nice pretty blue when I turned off the lights ... voltages checked fine. Well - ya get the point! This was a tough one! And now, almost all my tests and tweaks - trash can! I suspect it was losing G2 voltage. How would you even test for something like this? Maybe a socket adapter? Even pulling the tube partially out might affect things. So anyways, learn from my mistake.

AVOID these sockets! Save yourself some misery. These came from the auction site. I'm not bashing any particular seller either, but these "bakelite" sockets are JUNK! I suggest some ceramic sockets.
   
   
   

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44


Messages In This Thread
462ron - by 462ron - 10-15-2024, 09:07 AM
RE: HiFi (Chifi) tube amp build - but my own design. - by TV MAN - 01-13-2025, 12:29 PM



Users browsing this thread: 27 Guest(s)
[-]
Recent Posts
The list of my radio & TV collection!
Hello Peter, Thank you for posting that !! Sincerely Richardradiorich — 09:40 AM
Eico 232 VTVM Schematic
It's a microwave antenna. ?;-p?. I substituted 1N4002s off the 6.3 vac winding for the 1.5 volt battery. Uniprobe is the...RodB — 05:50 PM
Eico 232 VTVM Schematic
Try BAMA for a schematic. Looks like a replacement power source for the D battery has been installed. The tube may be...Chas — 04:51 PM
Eico 232 VTVM Schematic
Is that a battery holder?morzh — 04:43 PM
Eico 232 VTVM Schematic
A friend gave me this Eico 232 VTVM and I'm having trouble locating the schematic for it. This one seems to be a later v...RodB — 04:17 PM
Var resistor id
Considering what it is in series with, I doubt there should be any power requirements. Of course, we should know wher...morzh — 03:23 PM
Var resistor id
Trim pot, about 1/2 watt part of focus divider. As stated 2k ohms. This appears to be a rusty chassis, resolder all ...Chas — 03:19 PM
Var resistor id
Its a Sylvania 400 oscilloscope. here is a clip of r-100. Would be nice to know the current required. Not listed in part...Martinj — 02:10 PM
The list of my radio & TV collection!
Thanks Richard. I hope you enjoy it. Here I have created an English section on the history of radio with videos in Engl...RadioSvit — 10:23 AM
The list of my radio & TV collection!
Hello RadioSvit, first all happy new year ! I will watch your new videos this week. Sincerely Richardradiorich — 09:19 AM

[-]
Who's Online
There are currently 5709 online users. [Complete List]
» 3 Member(s) | 5706 Guest(s)
AvatarAvatarAvatar

>