Steel String Singer #001/#002/#004 Layout/Schematics

[pompeiisneaks]

I'm collating some basic info here from a recent thread. That thread has a link to many other threads, so I'll include it at the bottom if anyone want's to dig in more than what's here.

Some pictures and schematics:
======================
#001:
https://ampgarage.com/forum/download/file.php?id=54108
Layout by Aaron:
https://ampgarage.com/forum/download/file.php?id=24379

======================
#002:
https://ampgarage.com/forum/download/file.php?id=54112
Schematic: https://ampgarage.com/forum/download/file.php?id=54132
Original hand drawn one from above: https://ampgarage.com/forum/viewtopic.php?f=5&t=17827
Layout by Aaron:
https://ampgarage.com/forum/download/file.php?id=24378

gutshots of a clone of 002: https://ampgarage.com/forum/viewtopic.php?f=4&t=21508

======================
#004
Gut shot:
https://ampgarage.com/forum/download/file.php?id=54109
Layout: https://ampgarage.com/forum/download/file.php?id=54142

======================

I'll add more updates here as we have them.

Original thread:
https://ampgarage.com/forum/viewtopic.php?f=4&t=32016

[talbany]

History of the Steel String Singer amplifier
Dumble started making a series of amplifiers called the Dumbleland in about '66"
The Dumbleland was the predecessor of the Steel-String Singer." And according to the SSS data sheets, the SSS100W and the SSS150W both are guitar amps with the SSS being considered a "Lead Guitar Amplifier". In a Guitar Player interview, Dumble would go on to describe "The 'Steel String Singer' is designed to deliver the guitar sound necessary to fill stadiums and large halls. The power ability and tone circuitry work together to produce volume and tone of very exiting dimensions. The amplifier provides the player with a huge, clean sound that is enriched with a warm, singing quality". Although the Dumbleland (The amplifier Stevie Ray Vaughan used on Texas Flood) being the predecessor to the SSS they both shared similar features, utilizing both a High powered output section driven by a low impedance driver section as well as a High/Low filter tone circuit which follows the amps main TMB tone stack. Here are a brief description of how each feature affects the sound!.
Cathode Follower Driver section.12AU/12BH7
The main advantage to the cathode follower directly into power tube grids is losing the effects of grid-blocking from the coupling caps recharging and causing momentary distortion when power tube grid current occurs. The amp is overall tighter (electrically) without the time constant of the coupling caps. There also seems to be an added transparency, clarity and overall sheen to the tone with that style of driver for sure. The amp just sounds bigger and has more authority. Since the driver tube no longer has to drive a bias network or the miller effect of the multiple power tubes, I think overall bandwidth is improved along with a tighter more controlled and extended bass response. The driver also adds a unique compression to the amp that is instantly noticeable ( like the amp has a built-in compressor). The driver circuit also enhances the amps ability to sustain for long periods of time!
Step Filters
The next feature that was shared with the Dumbleland were the High/Low Filters. This feature was implemented after the main tone stack and also had it's own recovery gain stage. This allows you to broaden the amplifiers dynamic range within both treble and bass frequencies. The best way to describe these filters (without getting too technical) would be.
High Filter:
Each position of the "High" filters boosts a certain band in the high-frequency range. Similar to having an array of different value "Bright" switches, all with a different effect on the high-frequency-range.
Low Filter: 
If you turn this from left to right the "Lows" get more pronounced. It is a bit like having different "Deep" switch settings, each one with a different effect on the low-frequency-range to better match the low end to a particular cabinet type or speaker configuration
SPRING REVERB
The main difference between the Dumbleland and SSS being mainly the addition of long delay Spring reverb to the SSS. Dumble utilized several different type reverb circuits. Some were driven and mixed off the plates of the 2 12AX7's and some were driven off an added cathode follower Mixer requiring the need for an added preamp tube (#002 being the example) Both reverb topology provided a very lush natural sounding spring reverb that IMO far outperforms that of the AB763 design.
FEATURES
Given that the SSS was primarily a one-trick pony amplifier (Clean and powerful)it would appear that Dumble was more open to custom modifications to better suit his customers' needs. Because of this no 2 SSS were always identical. Some had true frequency Vibrato, some had the low impedance driver, some did not and most come with different output power ratings 100w/120w/150w and 300w versions depending on the customers' needs. Some used Dynaco iron, others used Fender/Schumacher or Peavey and even Triad. Tubes of choice were 6L6GC/6550/KT88
The SOUND!
The Steel String Singer is designed as a Hi Fidelity amplifier with large amounts of clean headroom and are complex amplifiers to build. In my experience playing an 002 version the only way to describe this amp is it is in a class by itself. There is really nothing to compare it to. Designing and building a tube amplifier that does not distort in some peoples minds defeats the whole purpose of using a tube amp given there most desired effect is its ability to distort generating complex musical overtones that made them famous by our guitar heroes. Because of this the SSS might not suit your style or musical taste you are chasing. Regardless as to whether you prefer a distorted amp over a clean amp like the SSS you will be hardpressed to find an amp that covers such a broad tonal spectrum and performs with such authority yet still extremely touch sensitive and articulate oh and "SINGS" quite like The Steel String Singer!.

Here are the different features along with the spec sheet of the (Known) SSS Amps and their serial numbers so you can decide which one is best suited for your musical needs.
Best of Luck!

Tony Albany


SSS #1 
"Silverface"
Owned & commissioned by Henry Kaiser
100w via 4x6L6's
Has single tube 12ax7 Opto Roach style tremolo
Fender Twin Reverb Pwr and OT
5 step filter positions on a high and low filter, 1 bypass for each
Low plate 2nd Gen Tonestack
4 tube Reverb
Standard Dumble PI
Cathode Follower Driver tube.

SSSnumber1.jpg

SSS #2: 
"Silverface" 
Owned by John Mayer, previously lived in Japan with the 2nd owner, and was owned and commissioned by Jackson Browne). 
100w via 4x6L6
Fender Twin Reverb Pwr and OT
5 step filter positions on a high and low filter, 1 bypass for each
Low Plate "Classic" Tone Stack
4 tube Reverb
Cathode Follower Driver tube
Ftsw'able PAB, Reverb Off ?

dumble-steel-string-singer-002620x291.png

SSS #3: 
"Silverface" with Snake skin Tolex
Owned and commissioned by David Lindley
100w via 4 6L6's, Fender Twin Reverb Pwr and OT
5 step filter positions on high and low filter, 1 bypass for each
Low plate 2nd Gen Tonestack ?
3 tube reverb
Cathode Follower Driver Tube
Ftsw'able FET and PAB Boost ( not proven, just assuming ?)

SSS2.jpg

SSS #4: 
"Blackface" 
Owned and commissioned by Henry Kaiser
the first of the "Black Panel" amps
100w via 4x6L6's
Fender Twin Reverb Pwr and OT
Low Plate Classic Tonestack
3 tube reverb
Ftsw'able FET and PAB
No CF driver tube

SSS3 (1).jpg

SSS #5: 
"Silver Face" 
Owned by Santana, 2 other owners previously, and Commissioned and owned by Steven Bruton and Eric Johnson
The first of the 150w amps
Peavey Transformers
Skyliner Tone stack
2 tube Reverb
5 step filter positions on high and low filter, 1 bypass for each
Ftsw'able FET, PAB, and Reverb Off
Cathode follower driver tube.

SSS.jpg

SSS #6 
Unknown?



SSS #7 
Silver face 
Owned and commissioned by SRV "King Tone Consoul" 
150w via 4x6550's
Tonestack ?
Stiff Pwr supply, more like a Dumbleland with Reverb than a SSS. Cathode Follower Driver tube.

Black Face 
Owned and commissioned by SRV
150w via 4x6550's




SSS #?

"Black face" 
Owned by Kirk Hammet, previously commissioned by Randy California or SRV 
150w via 4x6550's 
10 step filter positions on high and low filter, 1 bypass for each
Ftsw'able FET, PAB, and Reverb Off


And there are 2 more amps in existence that are in fact 150w Dumble SSS's.

Also there is the Silver Aligator SSS, that's actually a Dumbleland with Tremolo Commissioned by Ry Cooder and then sold to a different owner.
HERE IS A CLIP FROM THE MOVIE CROSSROADS
https://www.youtube.com/watch?v=ftRMqJaAFyITAKEN FROM THE DUMBLE SPEC SHEET

SSS SPECIFICATIONS 
Power Output: 150 watts of true power
Dimensions: 12”H x 28.25”W x 10.5”D
Weight: 80 pounds (head only)
Power Requirements: 120VAC, 60Herz, & 540VA at full output
Output Impedance: 4 ohms and 8 ohms switchable
Input Impedance: NOR = 1M ohm, and FET = 3.3M ohms

TUBE COMPLEMENT
4 x 7025 high-mu twin triodes
1 x 5751 high-mu twin triode
4 x 6550A beam power tubes

CONTROLS AND EQ SWITCHES
Preamp Controls: volume, treble, middle, and bass
Preamp Switches: bright, deep, rock/jazz, hi step filter & low step filter
Reverb Controls: send, and return levels
Master Section: master volume, and presence

SIGNAL CONNECTIONS
Inputs: NOR, and FET
Access ports: preamp out and power amp input (2.5V, 500K ohms)
Outputs: main speaker, and extension speaker

POWER SWITCHES
A.C. mains on/off
A.C. mains grounding
Operate/standby

REMOTE SWITCHING
Preamp boost on/off
Reverb on/off"
Here are all the Steel String Singers and Dumblelands listed in this 1986 price list:

Steel String Singer 120W.......$3,350
Steel String Singer 150W.......$3,520
Dumbleland Bass 150W.........$3,145
Dumbleland Special 150W......$3,390
Dumbleland Special 300SL.....$3,935

[pompeiisneaks]

already confused. Is there REALLY a .510 pF cap on the first stage? Or is it supposed to be 510pF?

Also question on preferences on the layout. I've got a pretty normal looking resistor, I was just going to color code the body brown/blue depending on the type, with the bands for the resistance, but not sure if that's acceptable. Screenshot of what I'm doing so far:

SSS-start.PNG

~Phil

[talbany]

already confused. Is there REALLY a .510 pF cap on the first stage? Or is it supposed to be 510pF?

Also question on preferences on the layout. I've got a pretty normal looking resistor, I was just going to color code the body brown/blue depending on the type, with the bands for the resistance, but not sure if that's acceptable. Screenshot of what I'm doing so far:


SSS-start.PNG

~Phil

Phil
Which amp are you doing?

T

[pompeiisneaks]

The schematic here in this post. I'm going off that schematic and one of the layouts. I figure once I get the layout in, I can tweak as needed. I may be doing the wrong schematic for the layout I'm on, not sure, but I'll atttach a screenshot of the segment I'm referring to:

picofarad.PNG

~Phil

[talbany]

The schematic here in this post. I'm going off that schematic and one of the layouts. I figure once I get the layout in, I can tweak as needed. I may be doing the wrong schematic for the layout I'm on, not sure, but I'll atttach a screenshot of the segment I'm referring to:

picofarad.PNG

~Phil

Looking over the schematic I posted I see a few mistakes use this one as it looks to be more accurate. The hand-drawn one you will find in this thread is the one taken directly off the original so you can double check against the PDF if you have any questions. You may also want to post this one instead of the one you posted in the previous thread to keep everything as accurate as possible. The C-tone layout is a different amp 004 so we should try to keep them separate. If you want to do an 004 layout off the C-tone schematic that would be your call however it would IMO be cooler to do 002 with the CF driver.

https://ampgarage.com/forum/viewtopic.php?f=5&t=17827
Tony

[pompeiisneaks]

Okay I've updated my original to use that schematic. Which of the above photo's are of the 002? The one I was basing mine off of is the top one with much higher resolution, but not sure if that's 002?

~Phil

[pompeiisneaks]

Progress is being made. I'll be doing more of course, but stopping for now.

SSS02start.PNG

~Phil

[talbany]

Phil .Looks good.
002 is the one in the middle. The top one is 001 it has a tremolo circuit.. 002 has 7 preamp tubes. The layout looks good so far but if I could recommend making the resistors as big as possible so they would be easier to read. Also what I generally do is crop each board in photoshop off the original picture. Bring it scale save it export it to Visio and overlay it on to your new board . Then drop in your eyelets to match the board you cropped. Once all the eyelets are there delete the overlay and start adding the components. it's really easy and much quicker. Let me know if you need help.
BTW. I generally do my layout without labeling my resistor values first. Just do the general layout. Ill then go back later with the schematic and label them numerically since some people might not know color codes. It's also easier on the eyes while your building. After that I'll then change the color of the metal films to blue and carbon films to brown or red with the Red Phiers mentioned somewhere in the legend. Also, ignore the voltages in the hand-drawn as they were measured in Japan??
Keep at it and THANKS for the hard work!
Tony

[SixStringBender]

Yes, do 002, pretty pretty please.

I'm not all about historical accuracy myself. I would do the Manning filters and the Manning bipolar power supply for the CF driver. It can be The Amp Garage SSS 002.

And what about the accuracy of the 100K volume pot? I tried that in a none SSS amp and the bright switch was useless because the tone was so bright with the 100K. I have read where others say the same. I don't think Dumble would have made such a useless feature. I know I wouldn't.

And why 220K cathode/control grid leaks on the CF driver? With the low output impedance of the CF driver, that resistor only needs to be 10 times the output impedance.

The max spec series resistance on the control grid of a 6L6 is 100K and for a 6550 or KT88 it is 50K. So for a quad of 6L6 (each phase has a pair in parallel) 47K would be ideal with 1.5K control grid stops and for a quad of 6550 (each phase has a pair in parallel) 22K with 1.5K grid stops would be ideal.

I know the max series resistance spec has long been abused with PI/capacitively coupled amps, but with the CF driver, why not optimize the design and have the output tubes operating comfortably within spec?

[pompeiisneaks]

Thanks Tony, I may do that, placing them has been a SLOW process. I have the resistors as is because I'm using sluckey's template and it has the bands. I do have RN65's I guess I could use and change colors etc.

~Phil

[pompeiisneaks]

Oh 'to scale' How do I know scale? I don't see any measurements of the boards here? I'll attempt to get them as close as I think makes sense, but it's going to be a guess only.

~Phil

[pompeiisneaks]

I like this technique, way faster, only took me maybe 20 mins to do this. Put a few components on for me to assist with scale.

Firstpass.PNG

~Phil

[talbany]

I like this technique, way faster, only took me maybe 20 mins to do this. Put a few components on for me to assist with scale.

Firstpass.PNG

~Phil

You got it!. Really the whole point of the layout is so they can download it and use your boards as a template to print it cut and drill theirs. If you want I can send you some component blanks I have for Visio.Yellow Spragues TVA's Phier resistors etc. BTW If you don't have a protractor you can take a tube socket and overlay it on your print out and just scale it to match the pinouts on the socket
BTW. You want to keep this as origional to 002 as possible!!. If people want to use a different set of filters or other mods explain what it does post that in the thread as a possible mod and let them decide. That's my advice
Tony

[talbany]

Yes, do 002, pretty pretty please.

I'm not all about historical accuracy myself. I would do the Manning filters and the Manning bipolar power supply for the CF driver. It can be The Amp Garage SSS 002.

And what about the accuracy of the 100K volume pot? I tried that in a none SSS amp and the bright switch was useless because the tone was so bright with the 100K. I have read where others say the same. I don't think Dumble would have made such a useless feature. I know I wouldn't.

And why 220K cathode/control grid leaks on the CF driver? With the low output impedance of the CF driver, that resistor only needs to be 10 times the output impedance.

The max spec series resistance on the control grid of a 6L6 is 100K and for a 6550 or KT88 it is 50K. So for a quad of 6L6 (each phase has a pair in parallel) 47K would be ideal with 1.5K control grid stops and for a quad of 6550 (each phase has a pair in parallel) 22K with 1.5K grid stops would be ideal.

I know the max series resistance spec has long been abused with PI/capacitively coupled amps, but with the CF driver, why not optimize the design and have the output tubes operating comfortably within spec?

Yep!. The 100k Volume pot is a typo it should be 1M. When I built mine I used 56K and 1.5K for the grids. I also think these are typos in the original as well. SO Phil if you want to make those changes I am good with this. Somewhere I have a list of some other changes I did. will post these later.

Tony