Exactly what i was looking for, after buying a guitar off facebook marketplace which had relatively small problems, I’ve learnt to do far more testing when buying second hand

Interesting speaker choice. Smooth cone because the power tubes are not meant to be driven to overdrive?

Love this guy stands behind his amps 👍

my next Surface project , a bi amp version of the Dynaco ST-70 .

Standby is not to be used as a mute.

I have a lot of higher end nos preamp tubes, I wonder how they would sound in this?🤔And since you don’t have to bias the power tubes, would KT66s drop in there?🤔 I think this could sound nut in my 2x12 w/a Fane F70 and a Celestion Alnico Gold🔥

Good Doctor, I wish I could get my hands on one of those babies! If you would see fit, in the future, to design and produce a "homie" version of it, with a few "modern" appointments, I would put myself on the waiting list right away! Honestly, I'm already tempted by many of your creations, but I unfortunately must be a bit more "target specific", so to speak. Anyways Doc, I love your stuff, many thanks for your awesome work!

any possibility you will be reviving this beast??

The simple answer is "YES"! You can run an 8 ohm output into a 16 ohm speaker load! - It just won't sound exactly the same if you ran an 8 ohm output into an 8 ohm speaker load. This should have been a 1 min. video!

I bought the Tone King Iron Man II for an attenuator and a huge bonus is the impedance matching switch on the back... (Also can run two cabs from amps that only have one output jack)

Vox trolly , so thts what they call it . Good to know . Thx Doc .

Anyone else got the Schiit Vali 3? Is it a real tube amp?

Just got this head, my first Z, and its just like this. Going straight in this amp with P90s is one of the best sounds I've gotten.

Thank You, Dr. Z! Thoroughly enjoyed and learned something new. Subscribed 12-26-24 👍😊👍

Merry Christmas Dr.Z!

I’m still crying about selling my Route 66 years ago! Best amp I ever had!

It blows my mind that someone works on amps and designs and builds them, that didn't play guitar at all when he started...How can you have that much interest in amps if you don't know what a guitar player wants? I get it now though. Much thanks to your designs

Nice-one Doc, Ii thiink I get it now. Does the bias pot raise/ lower both Output tubes simultaneously( in a clas ab amp) or does it balance between the two..eg if 1 is say 15ma and the other is 25ma are we looking for the average for both eg 20a each so we turn the pot too get 40ma? That's the only bit I don't get, thanks Doc Z.

So if i have an amp set to 8 ohms and it has dual speaker output and my cab has 2 8 ohm inputs can i run both outputs at 8 ohm or can i only use 1? Does using both make my cab resistance 4 ohms or are they both 8?

Can you use turret boards in a solid state amps?

This was the most helpful info so far with what to do/not to do with a head and cab. Thank you so much!

turn it down, they will last a lot longer.

U gonna overheat your tranny 😂😂

My Maserati has become my favorite amp. I’m getting rid of my Maz and my ghia. I may also be getting rid of my nova and who knows maybe my Z28 Mark two the Maserati is such a good amp

You can extend the life of your tubes just by dipping them in warm marmalade and giving them an hour or so to set, never mind all this technical nonsense.

I’ve had my CAZ for a couple years now and have always wanted to make a demo video of it. I can’t still figure out how to achieve that due largely in part to how many amazing tones you can get out of it. It’s a do all workhorse on a stellar level. I get lost in it for hours on end. It’s a time machine really. I couldn’t get along without it now. Amazing guitar amplification achievement that will no doubt be sought after in the future once people “get it”

I always thought the z28 was inspired by the brown deluxe - despite having a totally different topology. This one looks even more interesting again! You keep putting out unique designs!

This seems quite different. I love z tones, but sometimes find them a bit ‘hard’ whereas this one seems compressed in a vintage way. Gorgeous

and from 2 (amp) to 16 (cabinet) ohm?

OMG! Wow! What a great service! Makes me want to buy one!

Mines coming tomorrow!

Love how many times you repeated the lesson. I’ve now memorized. Thanks!

That spongey, fuzzy attack and sustain sounds like those old Fenders and Peaveys from the 70’s. Cool sound imo

Great Demo and great sounding amp , very versatile

Love that sound super good keep Rocking and Rolling

You hiring dr.z you have my dream job, i live in Strongsville , so im not to far. Ive built 100s of amp. Im not a expert but i can solder and build good.

I built a octal bassman afew months ago, but i used 5881 power tubes. And its got such a sweet sound. I used 6sl7 for the first 2 preamp tubes then used 12ax7 for the ltp phase inverter.

I have a question, but I'm not sure exactly who to ask. I have a 2015 Maz 18 jr reverb that started as a Mki combo and was upgraded in 2018 to a MKii head in red with the cream front baffle. But it doesn't have a cab. The amp is from Palen in Springfield MO, so do I go talk to them about this or do I talk directly to you? I'm just talking about a 1x12 open back in red, I have a mojotone bv25m I'm putting in there but I'll buy it loaded if I must.

Hey, Z .. What can you say about the MAZ Bluesman?

Post phase inverter master volume is choice. Have it on my oranger rockerverb and does wonders for the ears. The new x ray sounds excellent and on the short list. 😊

Lord!!! I once bought an amp from Carl, what a player and what a sound from the Z

Anyone got the heavy weighted one for sale? I dont mind the weight

V30 8 Ohm sounds different than 16 Ohm version. They sound different even if they are from the same production line. That's true for most speakers, though. One has to be extra careful with V30 speakers, though. Depending on what production year and country they come, they can sound very different even in the same impedance. So , tone wise, that's not a valid test because they are sounding different anyway. One could say put two of them in series, but then you introduce filtering from one voice coil influencing the other voice coil woth it's own inductance. Even adding high power wire resistors have an influence on sound but would be the closest match to transparent testing. Do not believe they do? Try cheap passive load box and observe loss of top end and overall sound quality. Tube amplifiers like to be at a certain power level where they sound good. If you can manage that level by using a higher impedance speaker when you have no other option, go for it. You got nothing to lose. It is the only option anyhow. Issues with tone happen when you are running it with small amp and low volume scenario where using to high impedance speaker will make it sound anemic. It just can't excite the tubes enough. It can't cause saturation either. It sounds sterile and weak. But if you can go loud enough, you will be fine. Some people think that if they load the amplifier with lower impedance speaker that they are safe if they keep the volume down. Well, they do not see the entire picture. By idling the most fixed bias, amplifiers are biased to 70 percent of they rated playe power. Cathode biased amplifiers do even go to 90 percent at idle. Therefore, loading 8 Ohm tap with 4 Ohm speaker will try to draw 140 % from the fixed bias amplifier even without playing it. With a cathode biased amplifier, you will be trying to draw up to 180% power even at the idle. And that percentage will only go up with yhe level until it reaches 200%. Some amplifiers can survive that in short term scenario but it will eventually break things in any amplifier. So never do that. The very same thing is true for no load scenario. No speaker connected might not kill some amplifiers directly, but it will definitely kill any amplifier over time.

Excellent video. Don't be afraid to use all the technical lingo. If they're here, they'll keep up.

Inspiring Story!!!! Mad Respect!!!

Gonzalez Kevin Taylor Frank Wilson Joseph

Preamp tubes in Ampeg B-15's

Just picked a Dr Z Hot Rodded Dr. Z Rx 2×12 combo, and I love it!!!! Man does it sing!!!!

Will it be possible to make an adapter to use a 6sl7 in a 12ax7 slot? 9 pin to 8 pin? are heaters similar?

nice!