Power scaling for 18 watter

longshins

hi there, what's the best attenuator/power scaling option for the 18 watt circuit? Ideally want to avoid an external device and have it built into the amp. Thanks!

simonk

I use a Dr Z BrakeLite with mine which works well and lives permanently in the back.

MtB

I've used VVR on my P1800, 18watt TMB and Tweed 5E3 to good effect. I've also tried brake lite and power brake, but found VVR to be the best for my amp use - at home plus twice monthly meet ups. I added a control knob the the face plate of all 3 amps - much easier than groping around in the back of a cab.

You can buy the kit from Ampmaker: http://www.ampmaker.com/store/VCB-VVR-kit-for-cathode-biased-amplifiers-ZK02.html
There are hints and tips here: http://www.ampmaker.com/infocentre/thread-151.html

jpfamps

VVR works well with 18W amps in my opinion, but less so with other amps.

John_A

jpfamps said:

VVR works well with 18W amps in my opinion, but less so with other amps.

+1  VVR is a piece of cake to install and works well on a 18 watter

monquixote

I have an 18 watter with power scaling I'd consider selling.

DrBob

Would my Budda Superdrive 18W be a Cathode based amp ?

DJH83004

DrBob said:

Would my Budda Superdrive 18W be a Cathode based amp ?

Yes, it is cathode biased, and as per MtB, have fitted several of the VCB/VVR Ampmaker kits for customers and always had very good results, and they are very reasonably priced.

Telejester

monquixote said:

I have an 18 watter with power scaling I'd consider selling.

What type of amp is it and is it head of combo ?

longshins

monquixote said:

I have an 18 watter with power scaling I'd consider selling.

If/when my 5E3 sells then I will be in touch.

longshins

Just another quick one, I've heard you get extra hum using the VVR. Any experiences with this?

jpfamps

VVR shouldn't increase hum; in fact it can be implemented in a way that reduces hum as the HT supply benefits from extra smoothing from the series pass element in the regulator.

The main problem with noise using VVR is a low voltage setting we DC can get onto pots and cause them to crackle when they are turned.

This problem is worse in amps using JJ ECC83s as these are more prone to grid conduction.

Modulus_Amps

The main hum issues I have helped customers with has been due to the location of the mosfet and AC wiring, it turns out they can pick up hum fairly easily, so general good practices need to be followed.