Ceriatone Forum

Does anyone have a schematic for adding a passive effects loop on an 18 watt TMB EF86 amp? I ask for a passive loop because a buffered loop would probably be much more difficult to install. I've got a Kleinulator on order so I will use that. Thanks!

Here's a link to one layout Nik has.

http://www.ceriatone.com/images/mods/TMBceriatoneEffect-Loop.jpg (http://www.ceriatone.com/images/mods/TMBceriatoneEffect-Loop.jpg)

Perfect! I didn't realize he had this posted in the site....thanks!

i´m also interested in adding a loop, would a delay pedal work good in this kind of loop? i need it after the gain.
thanks!

I should like to add a passive effect loop on my TMB ef86.

How to use a single effect chain for both the channels? Is it possible?

With this layout, the jacks are on the 16ohm transformer output,

if I what to plug a cab in 8ohm, could I do that or I must only pluf 16ohm cab????

thanks

With two FX jacks installed the impedance selector switch is removed to make room for one of them.  As a result the 16 ohm tap that is hard wired to the speaker jack is just an example.  OK to connect to desired impedance.  Just make sure the unused transformer taps are insulated and not touching anything. 


These are line level passive FX loops.  The pedal levels are lower gain but no problem with something like a Kleinulator or C-lator to boost the levels on the RETURN.  There are line level effects processors that work great in the passive loop.  My old TC Electronics G-Force is one example.  But if you plan to use pedals you need additional gain.


That would require a redesign to make the front end of the amp more like a Plexi with a mixer circuit to combine both inputs before the cathode follower driving the tone stack.   It is possible.  Shoot me a PM if you would like a concept schematic.  I was going to rewire my 18W TMB but found I didn't need it.  I like the non-TMB channel the way it is and driving the PI stage directly.  I also like the TMB channel for the scooped mid-range.  Best of both worlds but had to balance the overall gain between the two channels when jumped.  Easily done by using a lower gain cathode follow tube like a 12AU7.   Scott

Just trying to get a few questions answered before I thrown down some $$ my first build - this is the only layout that I've found online that does exactly what I want: both TMB and an FX loop!

The tube names shown at the bottom of the schematic show a slash between two different tube names.  Does this mean that either tube can be used interchangeably?  Should one stick to the tubes on either the right side or the left side of the slash?

Also, the first jack in the FX loop only seems to have 5 terminals.  Is this on purpose?

Finally, can this circuit be built as written on the layout with parts from Ceriatone (Tubes, Transformers, Chassis, etc), and the board/components sourced from elsewhere?  From what I can gather, Ceriatone supplies the board with components pre-assembled, and I'd like to be able to do that assembly myself. 

Thank you all for the link to the layout, and for any help you can offer me!

    The name on the left is the British designation, the name on the right is the American. An ECC83 is a 12AX7 and an EZ81 is a 6CA4. Same tube, different name, depending on country of origin. Many tubes are marked with both.

No, it is a mistake.   The missing terminal is the ground normally close section that is opened when a plug is connected.  In effect this is not used at all.  Just run the ground bar all the way across like the speakers and other effects jack.

You certainly can source all the parts and build your own but will spend a lot more cash.  For my blackflag JTM50 I purchased the chassis, faceplates, and hardware from Nik.  The Ceriatone plexi type faceplates are just simply gorgeous and the chassis a perfect match.  I supplied the transformers, tubes, caps, resistors, turret board, top coat wire, and cabinet.  The amp turned out spectacular.  Just ask Nik and he will bend over backward to satisfy your needs.  Again I paid well over $1K doing it separately but in the end got what I wanted.

Thank you grod915 and arledgesc, that is very helpful. 

The only reason I would want to source my own parts is because I think it would be fun to prep the turret board and solder the components together myself.  Do you think Nik would be willing to ship those parts unassembled?

That is fun to do and you gain a lot of experience doing it like that.  Give Nik a shout.  He usually gives me what I want at a really decent price.  If you want a more traditional board material then check out somthing like turretboards.com.   You will find board material, stakes, and staking tools for a truly roll your own amp.  The 1/8" board material is really nice.  I generally though like to buy pre-punched chassis in the configuration I need and pre-drilled board material.  Going totally raw is too much work but you will learn a lot doing that way.  Scott

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