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Hi

I want to fit a reverb to a DC30 build,i do not want to use the foldback type.

Does anyone know how Matchless and Badcat do this.
Thanks Ian

Check this out for a Chieftan Reverb. Probably very similar.
http://www.schematicheaven.com/newamps/ ... ieftan.pdf

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

channel no.2 is connected to the the second half of the PI.
The chieftain is only a single channel amp

I was just thinking from a reverb design persepective. It isnt so easy to find the right place to tap off & return without affecting the tone.
only did it on the 15.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Hi

are you hoping to have the reverb work on both channels? If that's the case, you will need to sum the channels just before the PI as i did. However, i did mine a while ago and have completely forgotten what i ended up with, hehe, but i will look and let you know. If you plan to have reverb on only 1 channel, it will be simpler. However, you will need to put a high-value series resistor into the signal path (Fender use 3.3 Meg, bypassed with a 10 pF cap) and so there will be some tweaking of gain structure involved. (I am assuming you would probably use the traditional Fender reverb circuitry?)

Also you'd need to make sure the filament winding on the power transformer can cope with the extra 600 mA of current for the 2 extra valves (tubes). One way to do that can be to remove the pilot lamp if it's a 6.3 V globe and replace it with a neon indicator, that can free up 150 or 300 mA.

BTW, is the amp already built? Is it a head or a combo? Putting a reverb spring into a head can be a real headache (pardon the pun) as proximity to the power transformer can cause hum. It can be done if space allows but needs planning and care, as does the location of the reverb spring return signal and reverb recovery preamp tube.

Let us know some details, i have built a tube-driven reverb spring into an existing head recently and managed to get it sounding very good without extra hum and noise, but it took a lot of thought and careful planning.....anyway, hopefully with more info myself and others here may be able to help you get a good result.

cheers, neiL.

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Lumbering dinosaur....what's a master volume?

Hey Crusty,

That would be an awesome addition to that amp. Especially if you got it installed so there was no tonal impact. Expect the same would work in a TC15 as well.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Wow, can you imagine. A TC-15 with all the bells and whistles, including reverb.
Always looking forward to tomorrow.
Later

Right,time to give you all more information.I have bought a empty matchless head cab.I also have the west Lab 30 watt transformers.I still need a chassis.The reason i want a spring reverb is the DC 30 effects loop is so basic.I have thought about fitting a parallel tube effects loop to each channel,i have used the torres design in my marshall amps and it works fine.Fender reverb is to surfy,i have tried fender reverb circiuts before in my amp designs,there ok in fender amps but no good in Marshall,vox type amps.I wish i could find a Badcat reverb circuit on the internet.

Hi

Reverb circuits are basically only simple gain stages (drive and recovery) and the spring. There are 2 main types of input to the spring....capacitor or transformer. The Fender style could be modified easily in the tone department by simply channging cap values. There are many types of springs available which will provide different sounds, and cap input sounds different to transformer input. You could also drive the input with a 6V6 or an EL84 if you have enough filament current available from the power transformer. (I have built several stand-alone reverb units driven by the Vox AC4 circuit)....this type of circuit could easily be incorporated into a head when the head is being built from scratch. (Of course available space can lead to a great deal of careful advance planning to get a good layout and quiet operation).

I opted to build a tube effects loop into my DC30 style head rather than reverb for greater versatility, and for reverb i can hook a stand-alone unit into the loop....i used the Kevin O'Connor loop as it is switchable between series and parallel. The issue of putting a reverb into a 2 channel amp and having it operate on both channels can bring many issues into play....do the Matchless and BadCat amps with reverb have it operating on 2 channels?

Stereo effects loops would then require a stereo reverb unit or some kind of switching arrangements to get reverb operating on both channels.

Have you studied the Vox reverb as it was installed in some AC30's?

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Lumbering dinosaur....what's a master volume?

i am interested in the Kevin O Connor loop ,could you please let me have the schematic.

Thanks

Interesting thread!

Crusty - if you peek into the 15 watt section, you'll see I'm considering either a reverb or a series/parallel effects loop for the TC-15 I'll be building. My original idea/plan was a parallel effects loop to plug in offboard verb, then thought that 'simply' adding reverb would be the easier way to do things. Reading your comments, I'm not so sure any more - how complicated is the effects loop circuitry? Feasible for a newbie? Since I know I'd like one or the other in my amp (reverb is the main concern, other effects are icing), I figure I should plan out the layout before I build anything instead of trying to mod things after the whole amp is together.

Mattia
Effects loops are very easy to install,i use one tube and a dual gang pot to mix the signal.I do not like series effects loop because it puts the whole of the tube tone direct through a efects processor.Ok when i started this topic i wanted to fit a spring reverb,but the discussions have made me wake up,spring reverbs create hum,i am going to fit a parallel effects loops in this DC 30 project.

Sounds lite exactly what I want/need. I figure I can just go make a spring reverb unit if I feel the need for one!

Have you got a link/info/schematic/layout/something of that nature for the loop you use?