Bass Amp for a friend

[Colossal]

Anything inspired by Rush is a gift to the world IMO. That amp is beautiful, man. I really like the board over the power tubes, socket screw access and all.

Thanks buddy!I wanted it to be simple but really solid. I would have used terminal strips for the power section but thought the board idea might be a little easier with the driver circuitry nearby. My friend is an ogre of a fellow so I really wanted the amp to be a brick and handle anything for years to come.

[Colossal]

Well, after working the amp hard, unfortunately, one of those wonderful Winged =C= 6550s turned out to bad and heading towards failure. A fifth fret, A string D would trigger it....The plate would vibrate like mad with a terrible "gaaaaack" sound It happened once during the week, then with increasing frequency with daily use, and when I was chopstickng the amp yesterday for its check-up, I finally found the culprit by tapping tubes. Tap...tap tap...tap...GAAAAAAK!..ok, bad tube I swapped the tube to the next socket over and the failure followed the tube. So, I need to get another quad of 6550s. Well, at least I have three others which all are still closely matched (all idling at the pretty much the same current), mostly, so I will repurpose a pair for a new push-pull project and then the single for a single-ended amp.

So, what do you guys like for new production KT88/6550s these days? JJs? EH? Tung-Sol Reissue? TAD premium select?

Thanks.

[bepone]

or you can move the amp on the chair by side
i'm blindly taking russian tubes..sovtek, electro haromix, tung sol is also russian.. JJ octals i'm avoiding, after many failures of "JJ" capacitors" and "JJ "rectifiers i'm not so sure in JJ ...

[Colossal]

or you can move the amp on the chair by side
i'm blindly taking russian tubes..sovtek, electro haromix, tung sol is also russian.. JJ octals i'm avoiding, after many failures of "JJ" capacitors" and "JJ "rectifiers i'm not so sure in JJ ...

Yes, I don't care for JJ power tubes too much. I found the glass on the EL84s to be very fragile compared to a Tung-Sol, for example.

[TUBEDUDE]

Well, after working the amp hard, unfortunately, one of those wonderful Winged =C= 6550s turned out to bad and heading towards failure. A fifth fret, A string D would trigger it....The plate would vibrate like mad with a terrible "gaaaaack" sound It happened once during the week, then with increasing frequency with daily use, and when I was chopstickng the amp yesterday for its check-up, I finally found the culprit by tapping tubes. Tap...tap tap...tap...GAAAAAAK!..ok, bad tube I swapped the tube to the next socket over and the failure followed the tube. So, I need to get another quad of 6550s. Well, at least I have three others which all are still closely matched (all idling at the pretty much the same current), mostly, so I will repurpose a pair for a new push-pull project and then the single for a single-ended amp.

So, what do you guys like for new production KT88/6550s these days? JJs? EH? Tung-Sol Reissue? TAD premium select?

Thanks.

I've had good service from the Russian Gold Lions. I get pairs from Upscale Audio. They weed out the chaff, then burn in the survivors for 24-48 hrs. of stabilizing before matching pairs, at real voltages. They perform as well as my last pair of G.E. 6550A's.

[roberto]

No need to buy another quartet, ask for a pair matched as your quartet, so you have the substitute and one more.

[Reeltarded]

haha it looks just like the pictures!!

AWESOME!!

[Colossal]

I've had good service from the Russian Gold Lions. I get pairs from Upscale Audio. They weed out the chaff, then burn in the survivors for 24-48 hrs. of stabilizing before matching pairs, at real voltages. They perform as well as my last pair of G.E. 6550A's.

Excellent, thanks for the tip, much appreciated.

No need to buy another quartet, ask for a pair matched as your quartet, so you have the substitute and one more.

Good call, Roberto!

haha it looks just like the pictures!!

AWESOME!!

Thanks dude!

[martin manning]

I've had good service from the Russian Gold Lions. I get pairs from Upscale Audio. They weed out the chaff, then burn in the survivors for 24-48 hrs. of stabilizing before matching pairs, at real voltages. They perform as well as my last pair of G.E. 6550A's.

Excellent, thanks for the tip, much appreciated.

You would probably need to send the pair of your current tubes that you intend to use so the seller can measure them on his equipment. There are probably only a few that can do that.

[Reeltarded]

Are you going to call it Event Horizon because of it's mass, or Bolide because of it's impact? I want to hear that thing throw stuff off shelves.

[Colossal]

Are you going to call it Event Horizon because of it's mass, or Bolide because of it's impact? I want to hear that thing throw stuff off shelves.

I like those names! New tubes should be back in it in a couple of weeks, so will try to get a clip. It really does get that Permanent Waves / Moving Pictures era tone with a Jazz Bass. The sound is both warm and springy, but at the same time, articulate with a lot of presence and harmonic haziness. You can set the EQ to dial in a tone, and then increase the Bass to bring in the (massive) low end to taste. All of it really could boil down to a jumpered Plexi input, set the EQ in a certain place, and just have Bass and Master knobs. I could see this being pretty amazing for guitar with a couple of minor changes. The AB2 driver really makes a difference. As has been described in some of the SSS threads, it extends the low end in more of a physical way (subsonic punch) and adds presence and clarity, but not in an in-your-face forward way.

[ViperDoc]

We need some clips!

Only for mild entertainment:
YYB
Cygnus B-1
Permanent Bass
Bass Under Pressure
El Basso Estrangiato

OK...that’s enough...

[Guy77]

Are you going to call it Event Horizon because of it's mass, or Bolide because of it's impact? I want to hear that thing throw stuff off shelves.

I like those names! New tubes should be back in it in a couple of weeks, so will try to get a clip. It really does get that Permanent Waves / Moving Pictures era tone with a Jazz Bass. The sound is both warm and springy, but at the same time, articulate with a lot of presence and harmonic haziness. You can set the EQ to dial in a tone, and then increase the Bass to bring in the (massive) low end to taste. All of it really could boil down to a jumpered Plexi input, set the EQ in a certain place, and just have Bass and Master knobs. I could see this being pretty amazing for guitar with a couple of minor changes. The AB2 driver really makes a difference. As has been described in some of the SSS threads, it extends the low end in more of a physical way (subsonic punch) and adds presence and clarity, but not in an in-your-face forward way.

Hi Dave, which tubes did you end up going with? I am deciding between Svetlana 6550S or JJ6550 or the EHX 6550 for a DumbleLand build I am doing.

Thanks!

Guy

[roberto]

Trumpet of Jericho? Was the sound that destroyed the walls of the city of Jericho in the bible.
Kagliostro suggested it to me for the GU-50 bass amp (still on paper).

[Colossal]

We need some clips!

Only for mild entertainment:
YYB
Cygnus B-1
Permanent Bass
Bass Under Pressure
El Basso Estrangiato

OK...that’s enough...

Well played I will try to get a couple of cell phone clips from my friend when it is back up and running.

Hi Dave, which tubes did you end up going with? I am deciding between Svetlana 6550S or JJ6550 or the EHX 6550 for a DumbleLand build I am doing.

Hi Guy,

I ended up with another quartet of Svetlanas (new production). They were reasonable. I will give the Gold Lions a shot, but not in this amp. The Svetlanas are a known quantity in this amp, so decided to just stick with them until it is certifiable again. They do sound very good. Very balanced and if you want low end, no problem. You won't need more than a 250kA pot's worth

Trumpet of Jericho? Was the sound that destroyed the walls of the city of Jericho in the bible.
Kagliostro suggested it to me for the GU-50 bass amp (still on paper).

Most definitely. That amp will destroy the world and surely if the Higg's Boson was not discovered at CERN, it will be confirmed with that GU-50 amp.