Solo Dallas - SVDS Replica

foxey · Post by **foxey** » 22 Mar 2019, 14:22

and now...

1590B size.

andregarcia57 · Post by **andregarcia57** » 11 Apr 2019, 19:55

apollomusicservice wrote:boby6kiler thanks, here is version 1.1 with some corrections.

What is the value for the diode and inductor L1? thankful

EddieTavares · Post by **EddieTavares** » 14 Apr 2019, 00:28

Those diodes are just for protection and the l1 is used to avoid noise from the power supply.

boby6kiler · Post by **boby6kiler** » 14 Apr 2019, 08:01

this circuit is present on rev 2 to have the 12v to 9v but in the rv 3 this circuit is not present and all is in 12v like the tower if i remerber corectly

EddieTavares · Post by **EddieTavares** » 14 Apr 2019, 13:48

This is a "cosmetic feature" trying to keep the same circuit of the original circuit.

caspercody · Post by **caspercody** » 07 Aug 2019, 00:37

Does anyone have a working build of this?

Tomrcarre · Post by **Tomrcarre** » 13 Oct 2019, 11:23

Hi, apologies for resurrecting this thread but does anyone have a copy of a working vero or pcb layout for this circuit? All the links posted by other members of the layouts seem to be dead! Looking forward to messing with this circuit

aion · Post by **aion** » 14 Oct 2019, 20:15

Tomrcarre wrote:Hi, apologies for resurrecting this thread but does anyone have a copy of a working vero or pcb layout for this circuit? All the links posted by other members of the layouts seem to be dead! Looking forward to messing with this circuit

Not exactly what you were asking, but later this week I'll have a schematic of the newer revision of the Storm from earlier this year, the one with the optical limiter instead of the compander. I will also be releasing a PCB along with it.

FuzzMonkey · Post by **FuzzMonkey** » 15 Oct 2019, 07:13

aionios wrote:I will also be releasing a PCB along with it.

Looking forward to it.

456Onno456 · Post by **456Onno456** » 17 Oct 2019, 16:12

aionios wrote: ... later this week I'll have a schematic of the newer revision of the Storm from earlier this year...

this would be great. Really looking forward to it.

There are a few thinks I would like to add for those interested in building this circuit. I will mostly refer to Patrice's schem v1.2 on page 4 of this thread. In that schem, there are still some 'errors' (potential corrections mentioned in this thread, but hard to find) - the most central ones are:

omit R14, C21 is 16pF and C22 can be made larger (220µF) for better noise performance.

a) On top of it, there has been some discussion on C18 (1nF vs. 4.7nF). I doubt anyone can hear the difference between a 2k2 - 1n vs. a 2k2 - 4n7 low pass (with typical guitar speakers not reproducing a lot above 6kHz). I used a 4n7 and made two other caps, 22n and 47n, switchable via an On-Off-On. This actually makes a difference and next time (or when rehousing the effect) I would go with a rat tone control that can by switched out of the circuit (this also has been mentioned in the thread). My guess would be replacing R19 with a 10k pot and cap (10n - 47n) from middle wiper to gnd + increasing R20 to 860R.

b) The other thing that is a nice addition is a 2k2 and 100n in series for IC1A. One end goes to Pin 2 and the other one to the junction of C1 and C2. Again I made it switchable.

I assume everybody knows where to include some 100k resistors to avoid pops when a) and b) are made switchable, otherwise ask.

My impression of the sound (used lin pots):

Input gain is only useful around 50% with humbuckers (maybe a little more with strats and teles). Lower settings do not add anything a normal boost wouldn't cover, higher settings make everything too compressed and thick. Played into a Plexi, the output gain adjusts the overall boost. Everything above 40% adds too much drive, hence overdriving the input tube of the amp, which adds some less compressed and slightly brighter distortion (compared to setting the input gain too high). At least that is how I perceive it. There is a small magical spot for input and output gain that adds compression and drive in a very musical way. The two 'mods' proposed above allow tailoring it even further (for me useful if switching from a superlead to a superbass).

maybe someone will find this info useful,

m.

madras · Post by **madras** » 20 Oct 2019, 23:04

Some time ago I build mine. I named it Schafer Replica Replica.

My project is based on schematics posted in this thread.

Regarding your tips:

456Onno456 wrote:omit R14

Correct, I have also omitted it.

456Onno456 wrote:C21 is 16pF

Correct, I have also installed 16pF.

456Onno456 wrote:C22 can be made larger (220µF) for better noise performance.

Good point, I need to check it. Because mine is very noisy especially on higher gains. Thank you for the hint.

456Onno456 wrote:On top of it, there has been some discussion on C18 (1nF vs. 4.7nF).

I installed 1nF. Haven't tried 4.7nF, but it should result with a little little bit darker sound.

456Onno456 wrote:The other thing that is a nice addition is a 2k2 and 100n in series for IC1A. One end goes to Pin 2 and the other one to the junction of C1 and C2.

I do not undestand the purpose. I made a quick simulation with added 2k2 and 100n in series. The result is the only change is gain of preemphasis stage increased by about 0.3 dB (between 100 Hz and 10 kHz).

The additional mod I made is I removed IC1B voltage folower, because it does nothing. It is becasue output of NE570 in compressor configuration already has buffering. So I decided to use IC1B at the input, because original 100k input impedance is quite low. So I used it to make switchable impedance change to 1M. In general I prefer stock 100k impedance. 1M input impedance makes sound too bright in my opinion - tested with T-Top and JTM50 replicas.

Photos:

Schematic:

At the end I can say I like to play with it. I do not have original Schaffer Replica to compare, but based on Solodallas videos my copy does pretty much the same. What is more in my opinion it behaves different than just plain linear booster. And it is true that usable gain volume is up to 30-40%, if you crank more you'll result with harsh sound. My usual setup is input potentiometer on 100% and the output potentiometer on 10%.

aion · Post by **aion** » 21 Oct 2019, 00:54

Forgot to link the thread, but here's the trace of the Storm I posted on Friday:

viewtopic.php?f=1&t=30183&p=277347

caspercody · Post by **caspercody** » 09 Jan 2020, 20:48

Here is a Vero board I made up, and I have built this and can verify it works.

Thanks
Rob

moonshiner · Post by **moonshiner** » 10 Jan 2020, 04:30

caspercody wrote:Here is a Vero board I made up, and I have built this and can verify it works.

Thanks
Rob

awesome thanks . which schematic did you use? Also if you have it can you post it. Most of these links are dead or way too fuzzy to read. Much appreciated SIR and thanks to all for the Hard work!

caspercody · Post by **caspercody** » 11 Jan 2020, 00:55

Here is the schematic I used.

boby6kiler · Post by **boby6kiler** » 11 Jan 2020, 05:24

probably the first revision of the tsr , if you build that with the same component of the tower ans add the missing little circuit with a pot you will have the same good result i think

moonshiner · Post by **moonshiner** » 11 Jan 2020, 15:34

boby6kiler wrote:probably the first revision of the tsr , if you build that with the same component of the tower ans add the missing little circuit with a pot you will have the same good result i think

What ? Missing little circuit ? Hmm ? Please explain

moonshiner · Post by **moonshiner** » 11 Jan 2020, 15:46

Waiting on some parts to make this . What is V1 and V2 on the Vero layout ?

moonshiner · Post by **moonshiner** » 11 Jan 2020, 15:51

caspercody wrote:Here is a Vero board I made up, and I have built this and can verify it works.

Thanks
Rob

What is V1 and V2 on this layout ?

caspercody · Post by **caspercody** » 11 Jan 2020, 18:59

Just a reference point for voltage contacts. so if I needed to connect to a specific voltage, I know where they are located on the board. As for building the vero, it means nothing.

Solo Dallas - SVDS Replica [traced]