Hi,

(1987 - Plexi copy) - I carefully wired up 2 new jacks as depicted in the wiring schematic for the Interupt fx-loop. I tried it out without any fx units in the new loop and to my dissapointment the amp made some additional squeeling noises which I could regulate with the treble knob. Something was clearly wrong and I was as nervous as hell so I quickly switched it back off again. Yet I checked out the schematic again and it was fine.

To be honest I do not understand how it can work with the jack sockets I have. My logic tells me that the normal signal from the treble pot needs to flow across from one jack to the other and then return to the phase inverter stage until an fx-unit is inserted. The sudden arrival of a jack socket to and from an fx-unit would bypass the 'across' mode - right? But I think it is the opposite...

Someone here said I need 'switching jacks'. So I ordered 2 x Cliff 6,3 mm Mono jack sockets which are supossedly "switched'.  Yet the 2 pins on the left run across the center of the jack socket yet they do NOT bridge all the way to the pins on the right - indicating that the right-hand pins are standing free. This means to me that the signal cannot flow across from one jack to the other when no fx unit is present (or something is going on inside which I cannot see...).

Either they should not be switched OR they have sent me the wrong ones.

BIG Q's :-  Does the schematic apply to non-switching jacks? Do I need switched ones at all and how can I see if they are switched?

Cheers Brett

Hi,

I have looked at some 'Power soaks' on eBay but they are expensive and there is also the problem that I will probably still need an od or dist pedal when I play in the rehearsal room or live. I borrowed that Hughes&Kettner Tubeman pedal which is very responsive and gives me a very good and smooth overdriven sound - sadly it is faulty so I cannot keep it. So I decided to buy some cheap pedals to try to reach the same sort of sound. None of them were as good as the H&K Tubeman. I guess tubes are better...

The H&K Tubeman comes fairly close to what I want but maybe there is something else which is even better. I might still try a power brake... Which tube pre-amps would you recommend?

Cheers Brett

Hi,

I recently bought my '1987' on Fleabay and it is still sitting in my celler waiting to be 'boxed' up - I am building a head cabinet for it. I have played it at normal room levels and it is a really nice jangly sounding amp - with a tube screamer pedal it is slightly darker, but not distorted enough - I also have a TubeMan preamp so that is enough for jamming at home.  I cannot wait to get the head cab finished so I can take to the rehearsal room and turn it up!!!

I will send some pics soon as I put 'Humpty' together.

Cheers Brett

I am reading about the MV mod with some interest - I was wondering how much gain there is with the MV. I am guessing that there is pleasant increase but not high-gain right? Like an old JCM 800 and not like a JCM 900?

Cheers Brett

Hi,

I would really like that too - I have studied the schematics and I am sure I could do that easily after 30 years of wiring simple stuff.

However I have a question left over from another post which left me scratching my head. I was told the signal would continue to flow uninterupted between treble pot and phase inverter until I add an fx- in the loop. When the cable is inserted in the fx jacksockets the direct connection would be interupted and the signal would be routed out to the fx. I would like to order the jacksockets - Is there a special name for these jacksockets or is that a standard function with them?

Cheers Brett

Ha ha!

I plugged in a cable from the 'send' of a Peavey 5150 into my Plexi 1987 and - WoW! Heavey Metal galore!

It sounded exactly as good as the 5150, but I could vary the tonality more with the 2 channels - and it had some Marshall El34 sound to it as well. I had it really hitting a sweet spot - thick & creamy with tons of sustain. I could not decide where to stand between the 2 amps!

So I can certainly say that this amp can handle all sort of preamps! Now I have to find a pedal or preamp which does crunch and lead solos.

I will try out the JCM 900 too and let you know how it sounds / reacts.

Cheers Brett

Hi,

I have received my Ceriatone 1987 Plexi at last - I bought it here in Germany via eBay. I am very impressed with it - I know already that it will be a great live amp - it is very loud and it sings lively at higher volume unlike my Marshall JCM 900 - which surely sounds ok, but is somewhat lifeless at higher volume (good sound, but the response appears to be governed - a Marshall DSL would be the solution...). As I do not always play loud then I thought I might be able to add the gain from the JCM 900 into the Plexi and try and get that 'DSL' balance.

Any ideas how to do that? The JCM 900 has a line out but I think it would be too weak.

Cheers brett

Hi wyatt, thanks.

I looked at the schematic and the wire between the treble pot and the resister gets split - the point of inception for the interupt loop (lol).

If I understand that correctly then I do not need anything else - right? You mention buffer but I do not need to add anything physically or do I? I am blindly trusting the schematic...

One question still left - if the line to the resistor is cut to the fx-loop and imagine the fx-loop is unused (for whatever reason...) then surely the treble pot becomes deactivated? I would need a short cable from Send&Return I guess..

Looking forward to any replaies - Cheers Brett

I am not an electrician, but I have been wiring guitars and cables for almost 40 years. I am sure I could manage this little mod myself - the diagram is great. Thx. for that.

One stupid question: what is a dumblator?

And will it work with pedals and fx-units with different impedances?

Cheers Brett