[leftside]

After a long week of work I decided to remove the LCD-4 and plug in the Stellia. Just went with a pair of power tubes for these. The LCD-4 and amp combo have such a thunderous bass, but I wanted something lighter tonight and therefore the reason to bring out the Stellia.

Well first of all, I've never heard the Stellia have such good bass, but certainly not as thunderous as with the LCD-4. This was perfectly fine for tonight. Even though this amp hasn't been designed for such a high sensitive/low impedance set of headphones, the Stellia still sounds very, very good. The best I've ever heard it. Far better than with the WA22.

Over on the Glenn thread people have asked if there are differences between the GEC B36/12SN7 metal base and pair of GEC L63 metal base. All three of mine are from the early 50's with the inverted saucer getter. I think there is a difference. I found the L63 to be slightly more detailed and clear, with a slightly wider soundstage. Bass is about the same. Will also try with a pair of GEC 6J5 coke bottle from 1949 tomorrow night.

 

[Ichos]

You've got a killer set up!

 

[leftside]

You've got a killer set up!

Thanks Ichos. I'm actually visiting Greece next year. Haven't been since I was a young teenager, so really looking forward to the trip as a slightly older man.

 

[Ichos]

Great if you are traveling to Thessaloniki shoot me a pm!

 

[leftside]

Great if you are traveling to Thessaloniki shoot me a pm!

That fine city was close to the top of our list, but we ended up deciding upon Athens and a couple of the islands a ferry ride away from Athens. Next time

 

[mordy]

After a long week of work I decided to remove the LCD-4 and plug in the Stellia. Just went with a pair of power tubes for these. The LCD-4 and amp combo have such a thunderous bass, but I wanted something lighter tonight and therefore the reason to bring out the Stellia.

Well first of all, I've never heard the Stellia have such good bass, but certainly not as thunderous as with the LCD-4. This was perfectly fine for tonight. Even though this amp hasn't been designed for such a high sensitive/low impedance set of headphones, the Stellia still sounds very, very good. The best I've ever heard it. Far better than with the WA22.

Over on the Glenn thread people have asked if there are differences between the GEC B36/12SN7 metal base and pair of GEC L63 metal base. All three of mine are from the early 50's with the inverted saucer getter. I think there is a difference. I found the L63 to be slightly more detailed and clear, with a slightly wider soundstage. Bass is about the same. Will also try with a pair of GEC 6J5 coke bottle from 1949 tomorrow night.

It appears to me, that there is a some kind of consensus that having two separate triodes instead of a dual triode of the same kind of tube, yields better sound. From the comments I have been reading it seems to be so across the board. It is not a night and day difference, but still easily recognized by many people.

 

[leftside]

I forgot that two of my power tubes had broken spigots/guides. Obviously inserting two power tubes incorrectly into an amp isn't exactly good for the amp. Luckily, I know my local tech guy quite well from the times I used to go and see him when I had vintage amps and preamps.

This was totally my fault, but Mischa has been great to work with, and has emailed my local tech guy diagrams and schematics to assist with the repairs. Hoping to be up and running again soon!

 

[mordy]

Hi leftside,
Broken guide pins happen to all of us as well as inserting the tubes the wrong way....I did it a few times with driver tubes but luckily the amp survived.
Here is a post from another thread that I posted - perhaps it will be of help:

These things happen. For me the easiest way is to stick on a little piece of red tape indicating the location of the ridge on the guide pin. If you look carefully at the base, you can almost always see a little notch where that ridge was located.

If you really are worried about the right orientation, you can buy octal rings with a guide pin and attach to the tube.
https://www.ebay.com/itm/6-Pcs-Vacu...115670?hash=item236ccb4316:g:QtIAAOSwacdZbjxB

 

[leftside]

Thanks @mordy. I did indeed mark on the tube base where the pin guide would have been, but totally forgot about it. I now have in big red letters on the tube white cardboard box "Missing pin guide!".

 

[Zachik]

@mordy - are you familiar with rounded ones for "fixing" KT66 with broken key (and rounded bottom)?

 

[mordy]

I am afraid not, but you could contact the people at VIVA tubes and ask them - they seem to offer good customer service and sell the KT tubes as well.
https://www.vivatubes.com/about-us-contact/
(They have a 25% sale for another day or so)

 

[mordy]

Hi leftside,
Another thought occurred to me: Since you are communicating with the amp designer, perhaps it is possible to incorporate a protective circuit that shuts off the amp if something is shorting out etc?
I know that this is feasible because the Feliks Audio Euforia has such a circuit and it saved my amp when I used a defective adapter.

 

[A2029]

Hi leftside,
Another thought occurred to me: Since you are communicating with the amp designer, perhaps it is possible to incorporate a protective circuit that shuts off the amp if something is shorting out etc?
I know that this is feasible because the Feliks Audio Euforia has such a circuit and it saved my amp when I used a defective adapter.

Unfortunately a complete shutdown of the amp could not be built into this particular circuit. However, all of the supplies in the amp are regulated, current limited, and reverse voltage protected. If there is a short, the heater supplies have thermal shutdowns. Unfortunately, it was not possible to build a thermal shutdown into the regulated high voltage supply, so a prolonged short will eventually kill the big beefy 9 amp MOSFET in that supply (this happened in leftside's amp).

 

[mordy]

I am sorry to hear about leftside's mishap - since the 9A MOSFET is very inexpensive I am hopeful that it won't be an extensive repair.

 

[leftside]

I am sorry to hear about leftside's mishap - since the 9A MOSFET is very inexpensive I am hopeful that it won't be an extensive repair.

S*** happens I'll be extra careful in the future to make sure I don't make the same mistake again.