Double SSS Preamp (inspired by 004&005)

[ElectronAvalanche]

IMG_0475.jpeg

Fellow Ampgaragists!

The new year saw my latest preamp project see the light of day. The „Double SSS Preamp“.

Inspired by the momentous „My take on the Eric Johnson SSS 005“ thread. My thanks go out to Rootz and Beasleybodyshop and all the other contributors to the thread. Also to Martin Manning for his revised Filter Section.

With the preamp pne can switch via relais between either SSS 005or SSS004 (in essence the Ceriatone schematic).

I made one silly mistake by mixing up 005 and 004 controls, so in my preamp 005 has a Deep function and 004 Rock/Jazz. Never,ind. Also I did not implement a LNFB on V1a of 004.

In the meantime I did put a 220k „FET simulator“ resistor on the last node of the power supply to get the voltages down to 187V on the 004 side on its V1a and to 180V on V1a of 005. The „mixing“ stage has around 203v on the plates.

Funnily enough both 005 and 004 sound quite distinct. 004 is more midrangey/woody in character. They both compliment each other nicely and OD pedals really sound great in front of the preamp.

The 1M trimmer before the Filter section of 004 only makes sense if set lower than 10k, anything above and the sound is extremely muffled.



Just wanted to share some pics of my build and as mentioned say thank you to the community!

Electron

[Bombacaototal]

Beautiful project, glad to see the final project and that the 004 info were useful! Great idea to have both circuits and the relay switch, super skillful. 005 with PAB and MID boost distorts really nicely..and as a clean platform works super well with humbuckers and P90s. 004 is beautiful with a strat, so indeed super complementary.

The schematic of 005 shows filters entrance resistor and cap in reverse. 100k is the slope and .01 (actually 0.1uF) should be the low

[bepone]

very interesting.. maybe will be on my list one day

[ElectronAvalanche]

Beautiful project, glad to see the final project and that the 004 info were useful! Great idea to have both circuits and the relay switch, super skillful. 005 with PAB and MID boost distorts really nicely..and as a clean platform works super well with humbuckers and P90s. 004 is beautiful with a strat, so indeed super complementary.

The schematic of 005 shows filters entrance resistor and cap in reverse. 100k is the slope and .01 (actually 0.1uF) should be the low

Thank you Rafael. I forgot to also thank you for pointing me to the 004 schematic.

I see what you mean with the filter entrance with the resistor and cap. I followed beasleybodyshop‘s schematic which has the entrance as in my handdrawn schematic above. Rootz schematic indeed shows a 100n after the 100k, but also the 1M after the plate. So maybe I should rework the 005 section or I need to change the title of this thread to Double SSS 004 and 005(as interpreted by beasleybodyshop“).

I need to think about this a bit

[jelle]

Sweet build!

[ElectronAvalanche]

Thank you Jelle and Bepone!

Coming back to the Filter entrance circuit.

There are at least four versions I know of:

002, Manning (tweaked 002), Ceriatone 004 (with 1M trimmer) and 005 (as per rootz). Unfortunately I do not have a way to simulate the impact of each of these if you would have a set filter array (e.g. Manning filter array).

I might go with the rootz style for the preamp 005 section, since this is based on the available pics of 005 clones.

Here is a little overview of the different entrance sections:

IMG_0481.jpeg

Best,

Electron

[rccolgan]

It is an amazing project and excellent execution! Thank you for sharing and following up. I am adding this project to my wish list!

[martin manning]

Very nice looking preamp there! The step filter input network determines the Hi-Low balance at the output, and the values I chose will produce approximately equal treble and bass attenuation for the modified selector networks and the R and C values I specified.

[dbharris]

Great looking build!

-Dan

[ElectronAvalanche]

Hi Ryan, hi Martin, hi Dan,

Thank you for the kind words!

@Martin:

Thank you for the clarification. Since I implemented your filter values I will keep the filter entrance circuit as is and not change to the one as per rootz schematic. The filters as per your tweak are very even and musical sounding.

Best,

Electron

Family picture:

IMG_0404.jpeg

[ijedouglas]

Wow! Looks amazing!

[erwin_ve]

Beautiful work, thanks for sharing

Erwin

[rootz]

I really like these preamps! Great work. I suppose you compared the SSS amps to the pentode pre. Do they have some common ground, what are the differences?

As for the filter input network. I found that the one in my schematic only sounded good with the filters I use. Not with Martins filters. Vice versa is also true. If it sounds good the way they are, it sounds good! Keep in mind 005 has very little gnfb. So little in fact that you don’t get motor boating when swapping the OT primaries. The low gnfb has a big impact on overall sound. The filters I use sound rather flat with lower gnfb imho.

[ElectronAvalanche]

Pentode_004_005.mp3

I really like these preamps! Great work. I suppose you compared the SSS amps to the pentode pre. Do they have some common ground, what are the differences?

As for the filter input network. I found that the one in my schematic only sounded good with the filters I use. Not with Martins filters. Vice versa is also true. If it sounds good the way they are, it sounds good! Keep in mind 005 has very little gnfb. So little in fact that you don’t get motor boating when swapping the OT primaries. The low gnfb has a big impact on overall sound. The filters I use sound rather flat with lower gnfb imho.

Hi Rootz,

thank you for your reply.

Here (see link above) is a little (excuse the shitty playing) clip showing the three preamps (Pentode, 004, 005).
Guitar: DIY Tele with DIY wound PUs, neck PU selected.
Preamps into Hughes&Kettner VS250 power amp into Ox-Box, using 1x12 GB25 model, SM57+Royer121 model, a bit of plate Reverb from OX. All preamps set to the same tone control settings (except 005 bass maxed) and Gain settings. High Filter is vastly different: 004 set to less high filtering than 005 (keep in mind 005 has improved Manning array). I personally think that in my preamp 005 lacks some low end (could be due to the reduced V1b cathode resistor being 0.68uf) which sharply contrasts to what you found.

Again, this should just give you some idea.

My take on this:
Pentode: more scooped, different mid content, sparkly, but still very woody low end on bass strings. Most refined Clean IMHO in this comparison.
004: pronounced mid bark/woody low end, sharper highs
005: rounder, but less mids, a tamed version of 004.

What do you think?

Best,

Electron

[rootz]

Sounds good! All of them, though I was listening to my iphone, so crappy speaker.

Played the black 100W 005 with some friends this weekend at Guitarking in Boekel in the Netherlands. One of them brought 4 vintage strats ranging from 56 to 62 and a very good Les Paul clone with original PAF’s. The sound of the 005 is instantly recognisable and turns heads. Lush and big sound. Very detailed high end and an abundance of low end. Different from the 4x 6V6 version one friend brought. That one is a bit more mid focused. Both first played through a 2x12 with new g12-65’s, then through a vintage 4x12 with vintage g12-65 speakers. After that we compared the amp through two 1x12’s. One with an evm12l classic and the other with a reconed evm12s. The latter was a really great match. Bit more mids, cutting clean sounds, but still that velvet high end. The others were no slouch either.

I’m set on the filters I have now. Only when someone dives in an Hi Plain Drifter or the real 005 we will know for sure what the cap values are. I experimented with the filters you use too, also with Martin’s iteration of it. I did not like them as much as the one I use now for the very reason you mention. The mids and high end became overbearing. I knew that was not how it supposed to be when I saw the settings of some HPD’s in clips: bass turned down, treble and mids up. High filter somewhere halfway. I couldn’t use the amp with those settings at all, till I adjusted the filter cap values! Also I read somewhere that the high filter steps were are very gradual. I think that was Brandon in a thread from about 2012. He just launched the amp. So I stuck to the 1meg/33p combo leading to the filter and used much lower cap values onwards as well as very little gnfb. That was my Eureka moment with this amp so to speak.

I sincerely hope you’d like to do a labor intensive experiment and compare my filter setup to Martin’s. I’m absolutely convinced Martin’s setup fits 002 or 004 better, but that it’s not optimal for 005.