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Little Dot I+ Tube Rolling - Page 127

post #1891 of 2866
Quote:
Originally Posted by gibosi View Post
 

 

The dots on the Westinghouse is a positive indicator that this tube was manufactured by GE. The made-in-Japan GE was certainly not made by GE. And I suspect that #4 was not manufactured by GE either. My GE has ribbed plates, like your Westinghouse. The smooth plates on #4 suggest RCA.

Thanks for the info!

post #1892 of 2866

Hi, I am having a problem with my new Little Dot I+ and WE 408A tubes.  The amp does not seem to work when I put the jumpers on the 408A side as described in the instructions.  I tried the 408A tubes with the jumper set to 6JI position just to see if the tubes work, and they seem to work okay, but when I put the jumper to the 408A position, nothing happens.  The tubes don't even warm up.  Wondering if it's a defect in my unit or if I'm doing something wrong.  I've noticed on youtube videos that other Little Dot I+ have an actual switch there, but mine simply has a jumper setting instead.

 

I did the following per the instructions:

 

Original jumper position for K1/K2:

 

408A   x [ x x ]   6JI

 

 

New jumper position for 408A tubes:

 

 

408A   [ x x ] x   6JI

 

 

Hope my little diagram makes sense, the square brackets are the jumper.  I can take pictures if it would help as well.

 

Thanks!

 

 

EDIT:  Here are some pics of what I have if it helps - https://www.dropbox.com/sc/jsw77ffcgbay1ts/AAD2nJxScXU0-V3NCMyZRTIHa#/


Edited by odinsride - 6/10/14 at 3:44pm
post #1893 of 2866
Quote:
Originally Posted by odinsride View Post
 

Hi, I am having a problem with my new Little Dot I+ and WE 408A tubes.  The amp does not seem to work when I put the jumpers on the 408A side as described in the instructions.  I tried the 408A tubes with the jumper set to 6JI position just to see if the tubes work, and they seem to work okay, but when I put the jumper to the 408A position, nothing happens.  The tubes don't even warm up.  Wondering if it's a defect in my unit or if I'm doing something wrong.  I've noticed on youtube videos that other Little Dot I+ have an actual switch there, but mine simply has a jumper setting instead.

 

I did the following per the instructions:

 

Original jumper position for K1/K2:

 

408A   x [ x x ]   6JI

 

 

New jumper position for 408A tubes:

 

 

408A   [ x x ] x   6JI

 

 

Hope my little diagram makes sense, the square brackets are the jumper.  I can take pictures if it would help as well.

 

Thanks!

Did you removed the jumper from both J1 and J2?

post #1894 of 2866
Quote:
Originally Posted by i luvmusic 2 View Post
 

Did you removed the jumper from both J1 and J2?

 

J1 and J2 jumpers were already removed from the factory.

post #1895 of 2866

How i wish i can help you But my LD 1+ was butchered see....

 

 

 


Edited by i luvmusic 2 - 6/10/14 at 3:51pm
post #1896 of 2866

I was looking at the manual and it looks like it's just a matter of removing J1 and J2 then switch to 408.I never have a 408 tube so i never tried this setup. 

post #1897 of 2866
Quote:
Originally Posted by i luvmusic 2 View Post
 

I was looking at the manual and it looks like it's just a matter of removing J1 and J2 then switch to 408.I never have a 408 tube so i never tried this setup. 

 

Yeah I did exactly as the manual says but just seems like when switched to the 408A side I just get no sound.  The unit powers on but that's it.  I'll post on the littledot forums to see if they can maybe replace my unit or something.  Btw, your LD looks absolutely insane lol, I have no idea what I'm even looking at (brand new to this stuff)

post #1898 of 2866
Quote:
Originally Posted by odinsride View Post

 

Original jumper position for K1/K2:

 

408A   x [ x x ]   6JI

 

 

New jumper position for 408A tubes:

 

 

408A   [ x x ] x   6JI

 

It does seem that something is wrong with your amp. The only thing this jumper does is switch the heaters between 6.3 volts and 20 volts. The fact that the tubes don't even light up in the 408A position indicates that the heaters are not connected to a voltage source. Other than rechecking your connections, it might be best to contact David ( little.tube @ gmail.com ) to see if he can help.

 

Good luck!

post #1899 of 2866
Quote:
Originally Posted by gibosi View Post
 

 

It does seem that something is wrong with your amp. The only thing this jumper does is switch the heaters between 6.3 volts and 20 volts. The fact that the tubes don't even light up in the 408A position indicates that the heaters are not connected to a voltage source. Other than rechecking your connections, it might be best to contact David ( little.tube @ gmail.com ) to see if he can help.

 

Good luck!

 

I emailed David and unforunately he is not able to help since I did not purchase the LD I+ through an authorized vendor.  I ordered a cheap multimeter to do some of my own troubleshooting with my limited knowledge of electronics.  I'm not sure what I'll be able to do, but at least I can still use the LD I+ with stock 6JI tubes.  Bummer that I can't get the 408A's up and running.

 

Edit: Another thing I wanted to mention - as I said before the 408A tubes work (and sound great!) when the jumper is in the 6JI position.  Is it okay to keep using them like that? I only tried it out for a minute to see that they work, but if it's okay to use them with the jumper in the 6JI position I'd be happy with that.  


Edited by odinsride - 6/11/14 at 4:16pm
post #1900 of 2866
Quote:
Originally Posted by odinsride View Post
 

I emailed David and unforunately he is not able to help since I did not purchase the LD I+ through an authorized vendor.  I ordered a cheap multimeter to do some of my own troubleshooting with my limited knowledge of electronics.  I'm not sure what I'll be able to do, but at least I can still use the LD I+ with stock 6JI tubes.  Bummer that I can't get the 408A's up and running.

 

Since your amp is brand new, I suggest that you contact the vendor and ask that your amp be replaced.....

 

In the meantime, a simple thing to try is swap out the two computer jumpers for a another pair. It is unlikely that they are defective, but it is certainly worth a try.

 

And once you have a multimeter, if you are very careful, you can try to measure the heater voltage at the socket and at K1/K2.

 

Good luck! :)

post #1901 of 2866

Ok so I got my multimeter.  The reading between heater pins 4 and 5 when the jumper is set on the 6JI side is ~7.2v, which I'm not sure if that's correct or not since you stated they should be 6.3v in that position.  Now the fun part comes - I switched the jumpers over to the 408A side, this time with the bottom cover of the amp removed and facing up, and as soon as I turn it on I see smoke.  When I take a closer look with a flash light, I see that pin 5 of the right heater has been over-soldered, and the solder is connecting with the leftmost (408A side) K1 jumper pin.  So yeah, I will definitely be sending this back for a refund and will order my replacement directly from LD so I get warranty coverage.  Thanks for the help guys...I'm off to a rough start with audiophile equipment so far, but I won't give up :)


Edited by odinsride - 6/14/14 at 9:10am
post #1902 of 2866
Quote:
Originally Posted by odinsride View Post
 

Ok so I got my multimeter.  The reading between heater pins 4 and 5 when the jumper is set on the 6JI side is ~7.2v, which I'm not sure if that's correct or not since you stated they should be 6.3v in that position.  Now the fun part comes - I switched the jumpers over to the 408A side, this time with the bottom cover of the amp removed and facing up, and as soon as I turn it on I see smoke.  When I take a closer look with a flash light, I see that pin 5 of the right heater has been over-soldered, and the solder is connecting with the leftmost (408A side) K1 jumper pin.  So yeah, I will definitely be sending this back for a refund and will order my replacement directly from LD so I get warranty coverage.  Thanks for the help guys...I'm off to a rough start with audiophile equipment so far, but I won't give up :)

 

Congratulations on solving the problem! It's a shame that your amp is defective, but it is very fortunate that you decided to roll 408A tubes now, and not a year from now, so you are able to make a strong case for a refund.

 

7.2v is a little high, but that is not surprising. The LD heater voltage is unregulated, so if the AC voltage coming out of the wall is a bit high (not at all uncommon) the heater voltage will also be high. Plus, with no tube plugged in, there is no load on the heater circuit. Typically, with a tube plugged in, the reading at the pins will be a bit lower. Anyway, nothing to worry about.

 

And IMHO, your decision to purchase your next amp directly from LD is a good one. They have one of the best warranties in the business.

post #1903 of 2866

Just got a pair of Tektronik GE 6AU6 8425 and man are they amazing without even burning in yet! Will post more details after I am able to listen for a while. I soldered pins 2 and 7 together inside the amp :) I think its a lot more ideal than the wire jumper method. 

post #1904 of 2866
Quote:
Originally Posted by plus9paradox View Post
 

Just got a pair of Tektronik GE 6AU6 8425 and man are they amazing without even burning in yet! Will post more details after I am able to listen for a while. I soldered pins 2 and 7 together inside the amp :) I think its a lot more ideal than the wire jumper method. 

You should try Yugoslavia 6HM5.

post #1905 of 2866

Are they comparable in sound? I am thinking about grabbing a set of the Tung Sol 6AU6 as well and possible another pair of these tektronix to hold onto just in case. 

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