6550s and the Model T

[mike_sims]

My 1st gen has Sovtek 6550's(?) in it I believe, and my 2nd gen has Svetlana 6550's in it. Ed pretty much nailed it with his response.

[chev]

finally my tech ordered the jj's 6550 instead of KT-88, I'm glad he did, so I got something different to compare then...I'm getting the amp back tomorrow!

[Walt-Dogg]

I was suggested a set of Ruby 6550s and a line up of a Tung-Sol 12AX7 a Penta AX7 and Sovtek AX7/phase inverter. Though after playing through my amp this week and rearranging the power tubes I was getting a good sound. It's just a matter of getting my tubes tested to see if they're still good or not and get that maintenance done.

[chev]

I just prefer the solid quality of jj's and it's price, it can be push hard and still sound solid & tight for a long time.

A full jj's setup with 6550 have awaken the demon inside my Model T with a powerful growl, crazy!

with the proper dirt everything becomes possible.

[Walt-Dogg]

I just prefer the solid quality of jj's and it's price, it can be push hard and still sound solid & tight for a long time.

A full jj's setup with 6550 have awaken the demon inside my Model T with a powerful growl, crazy!

with the proper dirt everything becomes possible.

The what I'm hoping are matched Telefunken 12AX7s and Slyvania 6550s sound really good at high volume with my RAT, I'm just not getting the tone I want, it's overall just a bit too sterile.

[EdBass]

Remember, a healthy amp is a clean amp when you are dealing with Sunn MI amplifiers, particularly from the era being discussed here. Tube rolling will certainly alter the tone, but you shouldn't get an appreciable increase in distortion by swapping tubes. The circuit itself will actually fight distortion, the "Ultra-Linear" circuit used by Sunn was actually originally designed in the 1930's to get the lower distortion (noise) characteristics of a triode while also utilizing the much more powerful output (but higher noise) of tetrode/pentode tubes.
As a "Sunn" side note, this "ultra-linear" design from the 30's was really made popular in the 50's by a series of technical articles by David Hafler; the same David Hafler who designed the Hi-Fi, low distortion Dynaco amps that Conrad Sundholm used as the basis for the Sunn circuits that this site is all about.

To get that over saturated tone that I often hear on the links posted here, well IMO there honestly are a lot of amps better suited for it than Sunns.

I've said it before, and I'll say it again; I don't think Sunn amps were chosen as the amp of choice of drone/doom/stoner aficionados for their suitability for the genres. I think it was because they were LOUD, and more importantly dirt cheap in the 90's, and as low revenue musical genres that require big power, they became “the” amp by fiscal default.
They were, and for the most part still are much, much cheaper than the Marshalls, Matamps, etc. of the era that are overall probably much better suited for the super dirty, heavy overdriven sound associated with those genres. A number of bass players across many musical genres have appreciated the Sunn “big clean” for decades, but they represent a fraction of the gear buying public; guitar players in rock, pop, country and most other commercially successful, big revenue genres have paid up for the “tone” amps for the last 30 years or so, making the “hi-fi” Sunns a real bargain.

Not so much now. 

Anyway, one of the side benefits of the Sunn circuit is that it will take pedals very well, and I would think that would be the way to get the amps to emulate the dirge tone a lot of the forum members seem to aspire to.

[madaradio]

Remember, a healthy amp is a clean amp when you are dealing with Sunn MI amplifiers, particularly from the era being discussed here. Tube rolling will certainly alter the tone, but you shouldn't get an appreciable increase in distortion by swapping tubes. The circuit itself will actually fight distortion, the "Ultra-Linear" circuit used by Sunn was actually originally designed in the 1930's to get the lower distortion (noise) characteristics of a triode while also utilizing the much more powerful output (but higher noise) of tetrode/pentode tubes.
As a "Sunn" side note, this "ultra-linear" design from the 30's was really made popular in the 50's by a series of technical articles by David Hafler; the same David Hafler who designed the Hi-Fi, low distortion Dynaco amps that Conrad Sundholm used as the basis for the Sunn circuits that this site is all about.

To get that over saturated tone that I often hear on the links posted here, well IMO there honestly are a lot of amps better suited for it than Sunns.

I've said it before, and I'll say it again; I don't think Sunn amps were chosen as the amp of choice of drone/doom/stoner aficionados for their suitability for the genres. I think it was because they were LOUD, and more importantly dirt cheap in the 90's, and as low revenue musical genres that require big power, they became “the” amp by fiscal default.
They were, and for the most part still are much, much cheaper than the Marshalls, Matamps, etc. of the era that are overall probably much better suited for the super dirty, heavy overdriven sound associated with those genres. A number of bass players across many musical genres have appreciated the Sunn “big clean” for decades, but they represent a fraction of the gear buying public; guitar players in rock, pop, country and most other commercially successful, big revenue genres have paid up for the “tone” amps for the last 30 years or so, making the “hi-fi” Sunns a real bargain.

Not so much now. 

Anyway, one of the side benefits of the Sunn circuit is that it will take pedals very well, and I would think that would be the way to get the amps to emulate the dirge tone a lot of the forum members seem to aspire to.

just gave you +1 for that.

I think you nailed it on the head with that one.  Well put.

[Rex B]

Hey. Just retubed my Model T with KT88s from Eurotube, and am amazed at the improvement.. Bob Pletka at Eurotubes is great, and knows his stuff.  Here's the link. You will probably need to adjust the bias.

http://eurotubes.com/

[mike_sims]

Anyway, one of the side benefits of the Sunn circuit is that it will take pedals very well, and I would think that would be the way to get the amps to emulate the dirge tone a lot of the forum members seem to aspire to.

Definitely a plus. I've had several amps that didn't handle pedals very well, but my Model T's sound incredible with them!

[Walt-Dogg]

Very much aware of all of that Ed, that's in fact why I'm looking at 6550s over KT88s, thanks. I'm just looking to get the most "open" raw tone out of the amp with a guitar straight into it, pedals can do the rest and to me it seems since the amp needs a retube, might as well look into what the tubes can do about getting the tone I want.

[clodo]

hello, sorry I do not speak English well. As I understand the 6550 is better? I saw  tung sol tube 6550, do you think it's good for a model T? Or is that "JJ KT88" are better

Thanks

[chev]

I have jj's 6550 in my Model T and the breakup is smoother either with the preamp crank or a any kind of dirt pedal.

My Solarus with jj's KT-88 is not as smooth and only seem to work good with an mellow OD pedal, Sonic Titan in my case.

With Fuzz it sounds too muddy to my taste, I guess that's what happen when the KT-88 works against you to get the signal as clean as possible.

I will probably put those jj's KT-88 in my Sonaro head I use for bass clean tone only and get some new jj's 6550 for the Solarus and see.

I could then make  a A/B comparition with my other Solarus on jj's KT-88 vs Solarus on jj's 6550...

[clodo]

Itu can tell me a bit of your solarus? I am interested in this head. It seems that it is the same as the scepter ?

[chev]

try searching the forum, their should be info all around.

you can get good info in this catalog thread:

http://sunn.ampage.org/sdp/index.php/topic,4178.0.html

I'm going out of subject but essentially, the Solarus is the same as the Spectre, the only difference was the cab combination.

Solarus came with a 2x12 cab, the Spectre with either a staggered 4x12, a 3x12 or a 2x15.

both should be 80w, with a midboost switch, reverb and tremolo, 4 inputs, volume, bass, mid, treble, presence, rate, depth.

12AX7, 12AU7, 6an8, pair of 6550 or KT-88, GZ34 rectified(been changed to solidstate rectified later with the 190L version), 4 or 8 ohm speaker outs, one of my Solarus came with 8ohm and 16ohm outs but I made it changed to 4 & 8 ohm.

these heads has no control on the preamp volume, only a master volume so you wont get dirt out of these amp unless you run them cranked with the midboost, and it's not a smooth dirt because they were made for a good loud clean. I prefer using a good boutique dirt in front with the midboost off.

for a 80w, it can over-power any 100w range amp easily out there...!