Blackstar HT-5 Tube Swap

Discussion - HT-5 amplifiers.
Post Reply
1995strat
Posts: 10
Joined: Fri May 28, 2010 12:00 am
Location: Cleveland

Mon May 31, 2010 2:56 am

Any thoughts on swapping tubes in the HT-5. Has anyone swapped out the 12BH7 without issues related to the bias?

6StringBender
Posts: 64
Joined: Wed Apr 28, 2010 12:00 am

Mon May 31, 2010 6:52 am

I haven't, but i'm planning on going with the Electro-Harmonix replacement when I do (provided theirs is of the same rating) instead of the Military Surplus tubes that most vendors have.
I'll likely be replacing it, and replacing the ECC83 with either a Groove Tubes or Ruby Tube this summer.

If anybody knows other sources for GOOD 12BH7A tubes, please speak up, because i'm not THAT fond of E/H, but they seem to be one of the few non-military makers of this particular tube.

1995strat
Posts: 10
Joined: Fri May 28, 2010 12:00 am
Location: Cleveland

Mon May 31, 2010 9:38 am

I have a NOS Tung Sol 12BH7A on the way, I picked it up on eBay. I'm really not that fond of the EH either. I just wish there was some info out there on biasing the power tube. I did put in a Groove Tubes ECC83 and it was an improvement over the Sovtek. I may try a 5751.

escargotomy
Posts: 8
Joined: Mon May 31, 2010 12:00 am
Location: New Jersey

Mon May 31, 2010 11:15 pm

New to the forum. Glad to be here! Funny coincidence, I have just bought a NOS Tungsol 12BH7 off ebay myself! It doesn't ship until tomorrow so I probably won't have it until the end of the week. Did a bunch of NOS research and it seems Brimar & Tungsol are the shizz when it comes to BH7's. But try to find a Brimar for under $75.. lol. I know it's the stereotype but I'm also in heavy bid rotation on NOS Mullard 12AX7's for my HT-5 but I keep getting outbid. I hope to land one for under $40 eventually. I bought the mini-stack HT-5 with the 1x10 cabinet, but that's going on ebay shortly as the Blackstar head sounds 1000x better driving my Fender Princeton Chorus (2x10). With that combo i get significantly improved clean headroom, reverb & chorus...sweeet!! Anybody have luck with different tube or cabinet combinations? Cheers, Matt B

sleepeatplay
Posts: 35
Joined: Tue Apr 20, 2010 12:00 am
Location: Vancouver, Wa.

Mon May 31, 2010 11:42 pm

I believe the HT-5 is self biasing. The pre-amp tube is going to be the biggest tonal difference. I put a tung-sol RI in the pre-amp spot.

6StringBender
Posts: 64
Joined: Wed Apr 28, 2010 12:00 am

Tue Jun 01, 2010 8:54 am

Welcome to the forum Escargotomy (love the s/n) !!!
I've mated my HT-5H with a really unique speaker cab, that sounds fantastic above & beyond my expectations.
I started with a shorted out Fender Frontman 60B Bass combo.........pulled the power chassis, made a new grille-cover frame & covered it with vintage Fender cloth (to cover the 2 1/2" gap left by the missing chassis) installed a 1/4" input socket into the back & drilled 4x1" "relief ports" into the baffle (1/2 way between the speaker edge & the baffle corners) .
Then I replaced the 12" bass speaker with a Jensen Vintage Ceramic series C12Q 35w speaker.
This amp reminds me of the description of the posessed girlfriend in "Ghost Busters"......."It Sings, it screams it barks,it growls" Image

I know I took the roundabout way to get a decent cab, but it sure beat tossing the old combo & paying retail for an anemic 10" cab.

Image[/img]
Last edited by 6StringBender on Tue Jun 01, 2010 8:58 am, edited 1 time in total.
Reason: Forgot to include pic !

escargotomy
Posts: 8
Joined: Mon May 31, 2010 12:00 am
Location: New Jersey

Tue Jun 01, 2010 6:47 pm

That's a handsome rig Stringbender. And thanks about my s/n...I always imagined it sounded like a good title for an unrecorded Floyd song (Sid, of course).

I've been playing through my Fender Princeton Chorus for about 17 years with an original RAT pedal. The whole deal cost like $300 when I was in college, and its always sounded so good I never thought I'd ever need a tube amp. But the reviews on the HT-5 have been so great that I had to bite. I never even thought it would sound as unholy good mated with my Fender but its just a match made in heaven. Hell I would've had to run out and buy a reverb pedal at very least.

1995strat
Posts: 10
Joined: Fri May 28, 2010 12:00 am
Location: Cleveland

Tue Jun 01, 2010 11:21 pm

The amp really sounds much smoother with alot more bass with the Tung Sol on the distorted channel. The cleans gets dirty quicker and just has more compression and alot more going on with better bass as well.

1995strat
Posts: 10
Joined: Fri May 28, 2010 12:00 am
Location: Cleveland

Wed Jun 02, 2010 1:41 pm

I just wish information was available on how to set the two bias trim pots. I think the amp sounds alot better with the Tung Sol 12BH7A but I want the bias and balance to be set correctly.

6StringBender
Posts: 64
Joined: Wed Apr 28, 2010 12:00 am

Wed Jun 02, 2010 10:29 pm

If the T/S replacement tube has the same rating as the stock tube, you shouldn't need to re-bias

Post Reply
  • Information
  • Who is online

    Users browsing this forum: No registered users and 8 guests