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Converting tube types. - Page 3

post #31 of 36

Ilikepooters- You just justified what I said -THANKS!!

post #32 of 36
Thread Starter 

Once i've made E80CC pin compatible with my Lyr, are there any other variables i need to be concerned about? I know E80CC draws 0.6A of heater current and that's fine, Lyr works happily with 6N1P's with the same heater current.

 

I know undervolting the anode will be fine, ECC85's (250v) work 100% and sound great at only 100v.

 

I know very little about anything else, want to make sure there's nothing dangerous in there that will either destroy my amp or make the tubes go pop and have broken glass everywhere.

post #33 of 36

ILIKEPOOTERS=They are trying to put you off-don't worry! -You are only changing ONE tube base connection that is PIN 9 on the tube base.

                               The original tube had that as a SCREEN connection -that is to screen the tube from radiated interference -old tubes had aluminum shields round them to do the same thing. You should find PIN 9 connection on the tube base is connected to earth / chassis- on your MM to earth it should read zero or near it -but you should see the connection.

                               Unsolder it so that NOTHING is on pin 9 of the base.

                                   Unsolder ONE of the wired connections to either 4 OR 5 .

                                      Move THAT connection to pin 9 of the BASE-solder it to it

                                        On the BASE pins 4+ 5 solder BOTH together so that ONE connection of the heaters is connected to BOTH.

                                             And remember when counting the tube BASE connections-FROM UNDERNEATH -left hand side clockwise is 1-2-3 etc. do not count from the top of the base - Every tube manual adheres to that policy. 

                                                The tube should light up in BOTH triodes  you should see that looking at the tube.

                                                    Once you do that and it works you can then try -ECC82 and ECC83 to see if you like them any better.

                                                        I have not mentioned changing any resistors but I notice that doesn't bother many people here  when they tube swap. So if its good for the goose its good for the gander. This isn't high tech doing this but I realize as has been said you have got to start somewhere and people shouldn't put you off  as this is a minor change in my book and if you do it right it should work.

post #34 of 36
Thread Starter 

I've made the adaptors and everything turned out great, many thanks to everyone for their help, the E80CC Tungsram's sound sublime beerchug.gif

 

 

 

For my next project, i want to make the Lyr use only 1 tube instead of 2, i know that Lyr uses both triodes on each tube.

 

What i need to know...

 

If i wire the pins together from one socket, will it double the voltage? i'm talking about A-A G-G K-K or to put it in pin numbers, 1-6 2-7 and 3-8, same for the other socket, then connect them to a single socket saver, so one tube runs both channels.

 

Anyone know if this will work? I'm guessing it's like parallel, so should be ok to do, but want to double check with the experts...

 

Reason behind this is 1 tube is A LOT cheaper than a matched pair.

 

Many thanks beerchug.gif

post #35 of 36

I just received my Lyr and have owned several hybrid tube amps as well all tube amps. I it is my understanding that with the Lyr it has four output power transistors devices which each triode drive each output transistor separately. With the Lyr it is important to have tubes with balanced trodes sections.  I do not see a easy way to have one tube to drive all four power transistors without modifying the circuit board and it would increase the tube load quite a bit. The lyr is a direct DC coupled amp and uses a Op-amp for DC servo control much like my Little Dot VI+.

I do have a special custom made voltage doubler adapter so that I can use of 12SN7 tubes instead of 6SN7 tubes in my other amps but that is a far cry to rewire the transformer for higher voltage only if the transformer has the required taps to do this.  

post #36 of 36

I'm pretty sure you can buy adaptors on ebay to allow other tubes to be rolled in the Lyr.

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