12BH7 and 12AU7 power section equipped amps are pretty cool

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tdbajus
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12BH7 and 12AU7 power section equipped amps are pretty cool

Post by tdbajus » Fri May 24, 2019 5:28 am

With all the princeton love floating around here, I thought I would sing a song of praise for the recent sort-of trent of making long-tailed phase inverter amps that are around a Princeton's wattage.

My Kendrick Solo7 is a pretty amazing amp- it has the only attenuator I have ever tried that I actually enjoy using. With one 12BH7 in the power section, it pumps out about 7 watts; with two 12BH7s, it gets right around the same stage volume as my Princeton.

While I think the stock Princeton clean sound is just amazing, I'm less enthused about how it sounds when distorted*. I prefer the buttery niceness of my BF Deluxe for that. The Solo7 gives me that, though it is much stiffer- it feels like I'm playing a little Twin rather than a little Deluxe. Kendrick has said their are mods I can do to the amp to soften it up a little bit. I might try those later.

Something else that bares mentioning is my Marshall JTM-1, which uses a 12AU7 in the power section stock, but sounds rather nice with a 12BH7. I haven't made my mind up as to which I prefer. It is an amazing recording amp- microphones love it, and the low volume means you can have it right in the room with you and not have to blast your monitors and piss off your neighbors.

I haven't tried out the Blackstar amps that also use a dual triode in A/B. I'm curious as to what people think about them.

*When you remove the negative feedback on a Princeton, the power section becomes very 5E3 tweed deluxe sounding, which is nice, but then I like the cleans less. Life is suffering.

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Re: 12BH7 and 12AU7 power section equipped amps are pretty cool

Post by rumfoord » Fri May 24, 2019 6:16 am

I have a tiny Blackstar HT-1 Metal. I only paid $130, so I probably wouldn't feel like it was such an adorable gem if it was as much money as a JTM-1 or anything. But I'm quite fond of it.

They seem rare, but in hindsight I'm kind of glad I found the metal version. I would prefer the clean channel on either HT-1, but I doubt the OD channel on the regular HT-1R would be very interesting to me. At least the metal channel is so over the top that it's sort of a fun and interesting toy. And if I put a huge reverb in front of it, I think I'd rather have the metal version for shoegazey ambience.

Anyway, the combo sounds like a small practice amp, but not too bad. And every time I plug it into a different speaker, I'm kind of impressed with it. I try to just think of it as a head with an emergency speaker than trying to fuss with fitting a Weber in there or something. At the moment I keep it in my living room with a 1x12 bass cabinet. I like it a lot, and I find myself wanting (to bother getting) anything in the between range of this 1W amp and my 40W amp.

[ps I'm on the side of the argument that says the clipping diodes in the circuit is not a big deal. I don't see any moral difference between this and just having an always on booster pedal in front of a tube amp—definitely not a deal breaker.]

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Re: 12BH7 and 12AU7 power section equipped amps are pretty cool

Post by tdbajus » Fri May 24, 2019 6:41 am

It's bizarre how much the Marshall 50th Anniversary amps are going for- I got mine for around $500 and the guy was happy to finally get rid of it. I bought it because my neighbors were complaining about my Vibro Champ being too loud. LOLZ.

Which amp has clipping diodes? The Blackstar? The Marshall?

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Re: 12BH7 and 12AU7 power section equipped amps are pretty cool

Post by rumfoord » Fri May 24, 2019 11:51 am

The HT-1 and HT-5 have some clipping diodes in there somewhere—apparently in a similar way to the Marshall Silver Jubilee (I think it was...some Marshall anyway). But this makes some people on forums get kind of, "YOU CAN'T CALL THAT A TUBE AMP!" Or like, "I guess it's good, but I prefer an all tube amp." I kind of get that, but fwiw I like this HT-1 better than the VHT Special 6 I had for a bit. In this size and price range, I'm glad I know about it but it's not the kind of thing that bothers me at all.

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Re: 12BH7 and 12AU7 power section equipped amps are pretty cool

Post by Steadyriot. » Thu Jun 20, 2019 3:09 am

Those Blackstar amps are great fun (though I just sold my HT100Metal because of the proprietary footswitches they use) and sound great!
The ht-50 is still one of my favorite tones out there. They sound great and are severely underrated.

Using triodes for the power stage in an amp is something that doesn't happen often but I think it's a great option for lower wattage amps. We're pretty stuck in tradition for as far as guitar amps go so this seems like a (sorta) fresh idea.

I've never heard of the 12BH7, do those work as preamp tubes too?
"If someone duetted with a Bald Eagle, they could rule the Country charts from here to eternity." ~shadowplay

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