H&K Switchblade 100w head - half power? [Archive]

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spyeman

10-11-2007, 03:54 PM

Has anyone with a Switchblade 100 watter researched whether it's possible (safely :)) to make it half power by pulling two of the four power tubes? I thought I remember seeing a thread on this, can't locate it. I've e-mailed the company, but not heard back yet. Thanks.

nickt

10-24-2007, 10:15 AM

Hi Spyeman
I've been trying to find that thread too! I seem to remember one of the guys had been told by H&K to pull the 2 outer tubes. I keep meaning to try it, but haven't got round to it yet. It's the only way I can think of to try and get the power section driving a bit!

nickt

10-24-2007, 10:26 AM

found it.

http://www.thegearpage.net/board/showthread.php?t=230008&highlight=switchblade&page=3

Laird_Williams

10-26-2007, 07:05 AM

I am not sure about the head - but I have the combo and did it.
It has worked great.

Just remember that the combined output load on the tubes changes - so the load conversion on the OT changes, which means the output load changes. Net: you may want to change where you plug in your cab. I plug my 16-ohm speaker into the 8-ohm output now. Works great.

Doing the above (pulling two tubes and changing where I plug the speaker in) also improved my sound substantially. Pumping 50Watts or so into a MASSIVE Toroidal OT Spec'd for 100 watts or more (which is what is in the 100W Switchblade combo) really improved my bottom end. Amazing what having enough iron in your rig does for you :-o

nickt

11-04-2007, 09:18 AM

Laird
was it the two outer PT's you pulled?

rcl

11-05-2007, 06:17 AM

Yes-the outer two tubes. Same for the marshall JVM,etc.

Orke

11-05-2007, 07:22 AM

Has anyone tried running an attenuator (sp?) on a switchblade? I thought I read once that you cannot but I don't remember why.

codeorama

11-05-2007, 10:39 AM

I called H&K customer service and they said you could pull the inner 2 or the outer two tubes.

bish0p34

11-05-2007, 03:23 PM

I pulled my outer two tubes about a year ago, and have had no problems playing out with it at least 3 times a week.

tythety

11-21-2007, 11:26 PM

Outer vs inner? I'm a dummy:

From left to right
1 2 3 4 tubes = X 2 3 X

Correct??

Laird_Williams

11-22-2007, 07:16 AM

Outer vs inner? I'm a dummy:

From left to right
1 2 3 4 tubes = X 2 3 X

Correct??

You got it.

bish0p34

11-23-2007, 02:59 PM

rockon1

11-23-2007, 03:18 PM

Although I pulled my tubes the day I got it, I have never changed the way I use the impedance jacks. I did about 6 months using an 8 Ohm single V30 cab, 2 months using a 16 Ohm 4x12 Red Bear cab, and the last 6 months using the 2 8 ohm 1x12 cabs. So far I've had no problems with this setup. What kind of problems would I have, and shouldn't I have had some by now(knock on wood)? I've pulled tubes on amps before and never heard of changing impedance with no problems...

Yop probably wouldnt have any problems. Its a mismatch of "one" setting and most amps will tolerate that. You will loss a bit of power whenever the impedance is mismatched either up or down so in this case your producing less than 50 watts. Bob

Laird_Williams

11-23-2007, 03:35 PM

Although I pulled my tubes the day I got it, I have never changed the way I use the impedance jacks. I did about 6 months using an 8 Ohm single V30 cab, 2 months using a 16 Ohm 4x12 Red Bear cab, and the last 6 months using the 2 8 ohm 1x12 cabs. So far I've had no problems with this setup. What kind of problems would I have, and shouldn't I have had some by now(knock on wood)? I've pulled tubes on amps before and never heard of changing impedance with no problems...

I doubt you'll have problems per-se. As stated here by others, you are well-within standard tolerences.

That said, I got much better sound by changing jacks after pulling the outer tubes. The amp just sounded "punchier". You might try it - just to see if you like it.