THD Yellow Jackets Questions

Hi,

I have a 100W head, but to coax any decent gain, I have to turn it up and it's a bit too loud (ok, maybe more than a bit). I did some research and one option is to use a set of THD Yellow Jackets.
So now, I have a few questions:

1.) There seems to be two types ('Cathode Biased' vs. 'Grid Biased'). How do I know which type I'm suppose to use?

2.) Will these allow me to get some decent amounts of gain at civilized volume levels?

3.) Are there any drawbacks to using these?

Any advice would be greatly appreciated.

First question, what amp are you putting them in, and what tubes are they going to replace? The grid bias models work in most of the amps I know of, but you can email them directly at [email protected] if you have any questions. I've met Andy and Ed, they're very nice people that will answer any questions quickly.

I really don't understand your gain question. Gain is going to come mostly from the front end of your amplifier. If you crank the amp, you will get some really cool output tube distortion, but switching to YJ's isn't going to reduce the overall volume of the amp that much.

There are no drawbacks to using YJ's that I've found. IMHO, they really sound best when you combine them with another set of tubes in a 100 watt amp. You would put the YJ's in the outer power tube sockets, and the normal tube in the inner sockets. The amp will take on the best characteristics from both sets of tubes!

I've had them in my Dual Rectifier since '02, and I don't see myself changing anytime soon.

i dig the groovetubes Substitubes more than the THD YJ's...

a/b'd them both, went with the GT SUB's..

they seemed better made...

they had a better feel.

took my MarkIIb 6l6's down to el84's, which is a cool thing..
that el84 chime, mixed with the classic boogie overdrive, pretty sweet.

I just bought a 100W Bruno head. This is suppose to be a high-gain head, but I can't get too much distortion out of it unless the volume is increased significantly. I was hoping that the yellow jackets would have the same effect as a power soak/brake (meaning that I can increase the master without disturbing my neighbours). At least this what people at GC have been telling me.

I was also under the impression that using a power soak/brake can be hard on an amp. Just wondering if the Yellow Jackets are just as hard on an amp.

make sure that they'll actually FIT in your head. the yellow jackets add a bit of height to the tubes, so if they're barely fitting in there now...

Thanks Redmax, I just emailed them.

Hey Gonzo, quick question about the Substitubes - when they need replacing, are you suppose to replace the entire unit or just the EL84s themselves?

Hey vds5000,

No, YJs or Substitubes won't make much of a volume difference-- that's for going from "really loud" to "loud."

As far as I know, attenuators are only hard on your amp/power tubes in the sense that you're going to crank it more because it's attenuated; you won't do any more damage than you would by just playing loud all the time.

I use a Weber Mass 150 on my Mark III sometimes and find it works really well for going from "oh god loud but it sounds so good" to "kinda loud but sounds good." It sounds really bad dialed down to the kinds of bedroom levels that other people are going for (I have a Rec Pre for that.)

However, my buddy's Roadster actually sounds good through the Weber down to, like, loudish conversation volume. I think it really depends on the gain structure of the amp.

Thanks CoG. I just heard back from Ed at THD, and he said the same thing - that I should use something like a 'Hot Plate'. So, how does the Weber Mass 150 compare to the THD product as far as sound, reliability and cost? Also, are there any other options/makes?

bottle rocket will disappear and change to different mesa amp names as you accumulate more posts

vds5000 said:

Thanks CoG. I just heard back from Ed at THD, and he said the same thing - that I should use something like a 'Hot Plate'. So, how does the Weber Mass 150 compare to the THD product as far as sound, reliability and cost? Also, are there any other options/makes?

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As far as I know the Weber is slightly cheaper and more versatile; it can take any output whereas you have to buy Hot Plates in specific ohm values. I've only ever owned the Weber so I can't really compare tonally. Weber also makes smaller versions (the 150 is for 150 watts) but you always want one that can take 50 per cent more wattage than the amp is nominally rated for. Dr. Z makes one called the Airbrake, Marshall makes the Powerbrake which is really frickin' expensive... just google on 'guitar attenuators' and you should see most of them.

Hmm, I've seen the THD ones used at GC on occasion. I wonder if that would be a valid option. Are these the types of things that I should stay away from used?

Is it me, or does the Gibson Power Stealth Power Attenuator look suspiciously like the THD Hotplate. Other than the colour of the body and the knobs/buttons - the layout is identical - even the labelling.

http://www.musiciansfriend.com/product/Gibson-Power-Stealth-Power-Attenuator?sku=481181

http://www.musiciansfriend.com/product/THD-Hot-Plate-Attenuator?sku=481283

vds5000 said:

Is it me, or does the Gibson Power Stealth Power Attenuator look suspiciously like the THD Hotplate. Other than the colour of the body and the knobs/buttons - the layout is identical - even the labelling.

Click to expand...

They are the same. THD makes them for Gibson, though the Gibson does look cooler.

Had the YJ's in a Fender Deluxe and they sounded great!

Ok, at the risk of coming across as a dullard, the ohms on the speakers (or attenuator) MUST be higher than what is on the amp, correct?

For instance, it is ok to plug an attenuator rated at 16ohms into an amp's speaker jack rated at 8ohms.

Or have I got that reversed?