[Athlord]

I made a couple of quick samples of the the two Slo's. The first riff is the SlO100, the second is the SLO50.
All pots are dialed in at 12:00.

https://soundcloud.com/guilese/comparison-slo-clones

To my ears the SLO50 sounds like a Behringer amp...

When it sounds like a Behringer, i think you build a Behringer....   

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The reason for the bad sound is not the power supply.
Please do what I have recommended:
Rebuild (= rewire) the AMP step by step.
Shorten the Cables to the Tube sockets
use different colors for cables
don´t tie Signal cables together

Regards
Jürgen

[Guile]

Does this link work: https://soundcloud.com/guilese/comparison-slo-clones/s-Iq8dW

[Stone]

Hi

I agree to Jürgen.

Why re-wiring and cleaning it up? It is hard to follow the wires within the pictures; also it might be hard to follow them with the amp opened up on the workbench - this is one of the major faults people do and have got in their amps.

Using different and correct color codes ensures that people are reading the same out of schemes and pictures of wiring - it is hard to tell about  the "thin black wire to the left" and the "a bit more meaty wire across the thin left black wire running to the right side" You get me?

Do answer your question concerning FX loop.

As far as I can see there is a 1k resistor soldered from signal tip to ground, which has to be 1 Meg (I cannot read the color code of it, so I might be wrong).

At second I cannot see how you made a ground connection for FX send jack and FX return jack. Are both jacks of switching type? I assume … check the wiring and if there is no ground connection you will not have any reference for the signal to be fed into another amp / fx return.

Do not use the shield as ground connection, as you will create a hum loop by using it in most cases (and I think so in this one).

The SLO is not the most complex and complicated amp, but it is also not a beginners DIY project … again, re-wiring will help to sort out things.

And if it comes to several amperes it seems current will always flow straight forward - but that 's another story

Regards, Stone

[Guile]

I ran the SLO50 (+ guitar) send into return of the SLO100. I have to open up the master and preamp of the SLO100 to have audible sound. Volume is very weak and thin with a hum.

[Stone]

I ran the SLO50 (+ guitar) send into return of the SLO100. I have to open up the master and preamp of the SLO100 to have audible sound. Volume is very weak and thin with a hum.

Yes - which is quite normal to my opinion if there is no correct ground connection of the fx send and fx return jack of the SLO50 (this could cause the weak sound internally of the SLO50).

Regards, Stone

[Guile]

Thanks for both replies.
Please tell me how to correct this. Would you have a comprehensible picture of the send/return?
Only the upper jack has a switch btw
could this be the cause of the bad sound?

nb I already reflowed all the solder points. I'm not sure that changing the wire of the entire amp and making the same connections will make the amp work though..

[Athlord]

I'm not sure that changing the wire of the entire amp and making the same connections will make the amp work though..

Currently your AMP looks like if someone had done spaghetti in the chassis....
The cables at the Tube sockets and many other are much too long - shorten the cables.
If you do not know how, look at the attached Picture....

[Guile]

I understand you don't like the way the amp looks, message received. But is there any proof that shortening the wires will change the way it sounds?
Thanks for the pic of Mike's work, true piece of art.

[Athlord]

But is there any proof that shortening the wires will change the way it sounds?

Yes, the Signal .... 

[Nils H.]

Hi,

I understand you don't like the way the amp looks, message received. But is there any proof that shortening the wires will change the way it sounds?
Thanks for the pic of Mike's work, true piece of art.

there are multiple reasons why you need to tidy up the amp. First, it's nearly impossible to debug an amp with a chaotic wiring, even if you have the amp in front of you and do know what to look for, much more so from pictures alone.

Moreover, loose wiring can cause all sorts of problems especially in a high gain amp such as the SLO. There will very likely be a lot of crosstalk in your amp, which can lead to multiple problems, including frequencies being canceled out and oscillation. Both problems are very likely to occur in your build.

There's a reason amps like the SLO are built the way they are, and those reasons are not purely esthetically.

Cheers Nils

[Stone]

Hi

For a short check it will be satisfying to draw a wire from fx loop jacks ground connection to speaker jacks ground connection - a detailed picture of the fx jacks can be found in Joachims "SLO 100 Schritt für Schritt" Thread at this point: http://www.tube-town.de/ttforum/index.php/topic,3292.msg31779.html#msg31779

There is also a pretty well working ground scheme http://www.tube-town.de/ttforum/index.php/topic,3292.msg36124.html#msg36124

To have the fx ground connected to speaker jacks ground is just for testing and may cause hum. But from my point of view it will not work without any ground connection.

If you are using a switched jack for fx send it will do (more or less if you are not using fx return with another preamp or so), but having both ones of switched type is the better choice (and ... which one is the upper one? Chassis top over on the desk or ... ;-) ).

Nils nailed it - shortening the wires leads to better overview and therefore analysis of problems is much easier. Some people build there amps in a very "esthetic" way if it comes to wiring, but the nice view is a plus beneath the elimination of all kind of unwanted noise.

Regards, Stone

[Guile]

Hi guys, thanks for the information and explanation, makes a lot of sense. I will get to it.
But the SLO100 clone which I bought a while back looks like this:
https://www.flickr.com/photos/115176149@N03/?
(Jurgen try not to vomit  )
It sounds great though.. And as far as I can determine it is the same as the SLO50. Same part-values and voltages.

I tried the fx loop instructions, but no result..

[_peter]

But the SLO100 clone which I bought a while back looks like this:
https://www.flickr.com/photos/115176149@N03/?
(Jurgen try not to vomit  )

Well, it does have shorter cables. 
At least where it counts.

Gruß, Peter

[Guile]

Hope this link works (grrrr): https://soundcloud.com/guilese/slos

All pots at noon

[Guile]

Hi

I agree to Jürgen.

Why re-wiring and cleaning it up? It is hard to follow the wires within the pictures; also it might be hard to follow them with the amp opened up on the workbench - this is one of the major faults people do and have got in their amps.

Using different and correct color codes ensures that people are reading the same out of schemes and pictures of wiring - it is hard to tell about  the "thin black wire to the left" and the "a bit more meaty wire across the thin left black wire running to the right side" You get me?

Do answer your question concerning FX loop.

As far as I can see there is a 1k resistor soldered from signal tip to ground, which has to be 1 Meg (I cannot read the color code of it, so I might be wrong).

At second I cannot see how you made a ground connection for FX send jack and FX return jack. Are both jacks of switching type? I assume … check the wiring and if there is no ground connection you will not have any reference for the signal to be fed into another amp / fx return.

Do not use the shield as ground connection, as you will create a hum loop by using it in most cases (and I think so in this one).

The SLO is not the most complex and complicated amp, but it is also not a beginners DIY project … again, re-wiring will help to sort out things.

And if it comes to several amperes it seems current will always flow straight forward - but that 's another story

Regards, Stone

Stone, the fx/send is in ordnung. Can you please tell me which setup to make?
Both amps on Normal channel
Send SLO50 to return SLO100
Guitar in SLO50
And then?