[lukeap69]

Yes
The Lundahl transformer has little 50/60 Hz magnetic field. This magnetic field can be picked up by the wiring.
Otherwise it sounds the same makes the same voltage. Except the old transformer has a 5 volt winding for a 5U4 , 5AR4 rectifier

Thanks. I supposed my OTL will have Lundahl, right?

 

[whirlwind]

 

 
The one in the classifieds is the one dubstepgirl listened to.
It is the basic amp no 6>12>25 switch and no 5998 switch can still use 5998s though
It will sound the same as whirlwind's amp though. And it has the normal 5U4 type rectifier but also can take the 3DG4 rectifier

 
Yep, it is kind of sad to list it but I just don't have time to listen to it plus I'm toying the idea of getting a 300B from Glenn in the future.

This would be a wonderful deal for somebody.....this amp is worth it for listening to HD650 alone  

 

[Wildcatsare1]

This would be a wonderful deal for somebody.....this amp is worth it for listening to HD650 alone  

I would love to pick it up for my HD800, hopefully it will still be available when I get back from Ukraine!

 

[gibosi]

  I am really interested in this configuration.  How does the c3g sounds with the 5998s?

 
I have the old transformer, the 5998 switch and C3g sockets. Very frankly, when rolling in the C3gs with 5998s (switch on) there is way too much ground hum. This is also true with the ECC31. However, with 6SN7, the hum is low enough not to intrude, but it is not totally silent. I trust Glenn will correct me if I am wrong, but I suspect a transformer that can put out over 11 amps in order to accommodate two 6336 is going to be somewhat noisy, unless you go with a Lundahl or similar premium product. So IMO, if you really like the 5998, you should get the upgraded transformer, especially if you want to roll C3g. And in general, if you want an amp that is totally silent, you should get the upgraded transformer.
 
Personally, I am very content to use GEC 6AS7 instead of the 5998. And given the cost savings, I am OK with a little background hum. Currently, I am listening with GEC 6AS7, Cossor "fat" 53KU and a Mullard ECC31 through HD700. There is a small amount of background hum, but it is low enough that it never intrudes and I rarely notice it.
 
So I would say the price of "quiet" is $300 and no 5 volt rectifiers. And I have absolutely no idea how the PY500 rectifiers compare. However, Whirlwind and I don't live all that far apart, so one day, I hope we can have a little mini-meet and compare notes.

 

[punit]

   There is a small amount of background hum, but it is low enough that it never intrudes and I rarely notice it.
 

I only notice it sometimes with certain tubes when there is no music. I have tried to see if i can hear it when music is playing but can't. Why does it go away when music is playing ?
I quite enjoy rolling rectifiers, so I would probably not choose the Lundahl (I assume you cannot roll rectifiers with the Lundahl, am i correct ?)

 

[gibosi]

  I only notice it sometimes with certain tubes when there is no music. I have tried to see if i can hear it when music is playing but can't. Why does it go away when music is playing ?

 
This is a good point. Like you, I only notice it when there is no music -- between songs or when there is a long pause. Once the music starts up again, I can't hear it.
 
Why? I would guess it is a function of the way our ears-brains work. When it is very quiet, it is almost as if we dial up our sensitivity in order to discern very small, faint sounds. But when our environment becomes noisier, our hearing seems to become less sensitive, perhaps to prevent some kind of overload. But this is just a wild guess on my part. lol

 

[gibosi]

  I quite enjoy rolling rectifiers, so I would probably not choose the Lundahl (I assume you cannot roll rectifiers with the Lundahl, am i correct ?)

 
When I search for PY500 in eBay, it appears that there might be a number of different manufacturers of this tube. But it might be that rolling is confined to only PY500 and nothing else. As I don't have this transformer, others will have to confirm....

 

[2359glenn]

 

  I quite enjoy rolling rectifiers, so I would probably not choose the Lundahl (I assume you cannot roll rectifiers with the Lundahl, am i correct ?)

 
When I search for PY500 in eBay, it appears that there might be a number of different manufacturers of this tube. But it might be that rolling is confined to only PY500 and nothing else. As I don't have this transformer, others will have to confirm....

You cannot use different 42EC4s but you can use different brands RCA made in USA Sylvania made in USA
GE rebrand made in UK Telefunkin  Panasonic made in Japan.
But not different types like you can do with the 5 volt rectifiers.
 
Punit if you want the 300B amp it will have the 42EC4/PY500 sorry.
I still have the original transformers for the OTL though. 
 
There is no background hum at all in whirlwind's amp with the Lundahl transformer.
The old transformer radiates a strong 50/60 Hz magnetic field as most E-I transformers do.

 

[punit]

 
You cannot use different 42EC4s but you can use different brands RCA made in USA Sylvania made in USA
GE rebrand made in UK Telefunkin  Panasonic made in Japan.
But not different types like you can do with the 5 volt rectifiers.
 
Punit if you want the 300B amp it will have the 42EC4/PY500 sorry.
I still have the original transformers for the OTL though. 

I was talking with reference to the OTL only.

 

[2359glenn]

 

 
You cannot use different 42EC4s but you can use different brands RCA made in USA Sylvania made in USA
GE rebrand made in UK Telefunkin  Panasonic made in Japan.
But not different types like you can do with the 5 volt rectifiers.
 
Punit if you want the 300B amp it will have the 42EC4/PY500 sorry.
I still have the original transformers for the OTL though. 

I was talking with reference to the OTL only.

OK
It makes things worse with the output transformers sitting next to it picking up the magnetic field.
Then I would have to go to a split chassis like Woo does and that would increase the cost of the amp.

 

[3083joe]

When I search for PY500 in eBay, it appears that there might be a number of different manufacturers of this tube. But it might be that rolling is confined to only PY500 and nothing else. As I don't have this transformer, others will have to confirm....

I hear the mullard PY500 is nice

 

[3083joe]

OK
It makes things worse with the output transformers sitting next to it picking up the magnetic field.
Then I would have to go to a split chassis like Woo does and that would increase the cost of the amp.

Is this an option on your 300b?

 

[TonyNewman]

I hear the mullard PY500 is nice

 
Langrex has a large stock of them, labelled as Granada Television. I have a bunch waiting for my Glenn 300B amp. Nice looking tubes.
 

 

[jc9394]

Glenn, do you still make a 300B amp with C3g?  I brought brunch of them last year.

 

[TonyNewman]

  Glenn, do you still make a 300B amp with C3g?  I brought brunch of them last year.

 
I can answer that one - YES - Glenn is making a C3G / PY500 / 300B amp for me right now <insert image of a crusty grandfather in basement tinkering away>