Marshall TSL-100 Spring Reverb Driver

[pyreweb]

Hello, I am hoping to build a stereo spring reverb setup. I am very keen on the sound of the Marshall TSL-100 spring reverb system, and so I will be aiming to duplicate it. These are the official schematics from Dr. Tube:

TL10-63-02_(1998)_iss4.pdf

Is it ok to just include that page of the schematics, or would it be helpful to include the other pages as well, to see the connections?

Thank you.

[motterpaul]

You need to take a close look at the way they power reverb tanks in tube amps. Springs require pre-amps to drive the springs and to recover the sound coming off the springs.

Inside tube amps, because they run off of "mains" transformers, you have access to much higher voltages. This one in your schematic appears to work off of 63v DC. It also takes a 12-pin quad opamp.

When I installed my reverb into my JCM800 I used a standard effects loop made to power 9V effects. I built a send/receive dual preamp with a quad opamp (send & recover) with an 18v charge pump. I found the specs for it in another DIY site but there is also one in this site called "spring reverb driver" which is similar to the one I used.

I choose to go with the effects loop route because I don't that much about changing voltage as needed inside of tube amps, and the effects loop I bought (metroamps) figures that out for you with a series of optional resistors you tie to B+ inside the amp to drop the voltage to 9v DC.

I don't know if that makes sense, but it will if you look at it long enough. I am still using mine happily and very glad I did it.

[pyreweb]

Thank you, that is very helpful to know and has probably saved me a lot of money, and perhaps electrocution. I had noticed that the capacitors were in the 60 volt range, but had not even seen that the supply voltage was that large. I suspect it would have gone very wrong. I will probably try the spring reverb driver instead. Is that the Dogenigt one or the Centre Stage?

[Beaker]

The Surfy Bear is on here too. That's a good one as it is optimised for one of the most commonly available Accutronics tanks, works with other tanks over a wider impedance tolerance than other drivers and most importantly, sounds great.

[motterpaul]

BTW:

I just checked and I am pretty sure the TSL uses digital reverb anyway, so that would change things.  

Here is my thread on how did my spring reverb, though, and the pre-amp circuit I used. It is close to the ones on this site, except I felt the one I included showed the grounding to the reverb tank a little more clearly - not that it is complicated, but when you have a lot of details on your mind sometimes life is easier with one less detail to figure out on your own.

http://guitar-fx-layouts.42897.x6.nabble.com/Spring-reverb-driver-td22936.html#a22954

I used the Metropolis effects loop.

Now, I don't know if your target amp already has an effects send, or if it even has a spring reverb. What amp do you want to add this style of reverb to?

[motterpaul]

Beaker is right - it is important to not only check the spring unit brand, but also the model number. There are two, three and four-spring models.

There are also charts out there which show how to recognize which model you have if it is a different brand name. For example, mine was an different brand but it fit the dimensions for aa 9-inch 4 spring Accutronics, and sure enough my pre-amp seems to be the perfect match.

If you have a different reverb, then you might need to find a different preamp or make some mods. This one comes with drive and mix controls, though, and both work well enough to give me a full range of reverb options from just a hint to swimming.

Obviously I am happy with it, one of the best amp mods I ever had. I don't like amps without reverb, and I also dislike trying to manage a reverb pedal in front of the amp which changes volume every time your switch pedals. But if you already have an effects loop, a digital pedal works about as well as a spring, that is just a matter of taste.