Dual recto 100 watt to 50 watt tube pulling/impedence ?

[hydro]

Hi,

I have a dual recto 3 channel - without power scaling.
I know that pulling one pair of tubes and a rectifier out of a 100 watt Dual Recto will convert it to 50 watts.

Two questions -

1) I know the outer power tubes and the two inner ones are paired. Does it matter which rectifier tube you pull of the two?

2) I have heard people say that pulling power tubes will change the impedence outputs of the amplifier; is this true, and if so, how does it work; i.e., if I have a single 8 ohm cab plugged into the 8 ohm output, would I instead use one of the 4 ohm outputs now?

 

[Authorized Boogie]

Hi,

I have a dual recto 3 channel - without power scaling.
I know that pulling one pair of tubes and a rectifier out of a 100 watt Dual Recto will convert it to 50 watts.

Two questions -

1) I know the outer power tubes and the two inner ones are paired. Does it matter which rectifier tube you pull of the two?

2) I have heard people say that pulling power tubes will change the impedence outputs of the amplifier; is this true, and if so, how does it work; i.e., if I have a single 8 ohm cab plugged into the 8 ohm output, would I instead use one of the 4 ohm outputs now?

It doesn't matter which rectifier tube you pull - either is fine. And be sure to half the impedance. Thanks!

 

[jbird]

But is there really anything to gain from this?

 

[hydro]

It doesn't matter which rectifier tube you pull - either is fine. And be sure to half the impedance. Thanks!

meaning, use the 4 ohm output for an 8 ohm cabinet, correct? Or use the 16 ohm output for an 8 ohm cabinet?

 

[hydro]

But is there really anything to gain from this?

It's probably mostly academic; mainly I just wanted to know since I had heard you could do it. One reason would be if you are low on tubes/lose a tube and don't have a spare, which can happen. Another would be to get more power tube distortion at lower volumes.

 

[Authorized Boogie]

Yes, you would use the 4 ohm jack on the amp with an 8 ohm load. Pulling a pair of tubes will half the wattage, which is about a 3dB decrease in volume, and will lower clean headroom. And absolutely a great way to make it through the gig if one tube goes and you don't have a spare! Thanks!

 

[hydro]

Yes, you would use the 4 ohm jack on the amp with an 8 ohm load. Pulling a pair of tubes will half the wattage, which is about a 3dB decrease in volume, and will lower clean headroom. And absolutely a great way to make it through the gig if one tube goes and you don't have a spare! Thanks!

Ok, thanks very much!!

 

[Gibson07]

Yes, you would use the 4 ohm jack on the amp with an 8 ohm load. Pulling a pair of tubes will half the wattage, which is about a 3dB decrease in volume, and will lower clean headroom. And absolutely a great way to make it through the gig if one tube goes and you don't have a spare! Thanks!

So for a 16 ohm cab pug it into the 8 ohm hack in the head?

 

[Authorized Boogie]

Yes, you would use the 4 ohm jack on the amp with an 8 ohm load. Pulling a pair of tubes will half the wattage, which is about a 3dB decrease in volume, and will lower clean headroom. And absolutely a great way to make it through the gig if one tube goes and you don't have a spare! Thanks!

So for a 16 ohm cab pug it into the 8 ohm hack in the head?

Correct

 

[npo12354]

I second the notion that it is a great way to get through a gig if a tube blows. Personally, I didn't like the results of doing this purely based on how it changed the overall sound of the amp. Although I did love the lowered headroom since it was definitely noticeable.

 

[UnderJollyRoger]

Pardon me for hijacking, but out of curiosity, can you run a newer Multiwatt-Rectifier in the 50 Watt Setting ONLY with the outer tubes or does the inner pair needs to be plugged in, even when it is switched off ?