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Messages - Cookymonster

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The Fender Rhodes Electric Piano / Fixing the harp on the treble side
« on: April 30, 2021, 09:36:55 AM »

I was just wondering.
The positioning of the treble part of the harp.  Is it always best to fix it where the tones ring loudest ?  There is not the same movement space as on the bass side.
It can bemoved between the hammer getting stuck on the tine block and no sound of the small tine. So about maximum an inch / few centimeters.   As the sound of the treble section can not be customised like in the middle section, I always start looking  for the loudest, best ringing treble tones and then fix the harp with one screw.  After that I start shifting / moving the harp  for best tone / strikeline ... not always the loudest tone... but a lot of times, though.  Thanks for advise.

The Fender Rhodes Electric Piano / Re: How good is the Bump Mod?
« on: April 18, 2021, 10:16:56 AM »
If the hammer is on the bottom in in rest position, and if the stop-lock position remains the same, then the "hammer throw" distance has not changed.
What changes is the "lever"-action.  In both yours and my mods we extend the lever.  That results in lighter action.
On the other hand, in the old action, a short but heavy strike will cause more "inertia"... which overbridges the escapement space (between stop-lock and the tine)  with more violence.
This gives more "whack".   That's my theory.  Although I must admit that there may be a healthy compromise. In some Rhodes piano's  the action is so heavy that you can actually feel the resistance from the sliding of the felt.  So I may remove my diy extension. Not sure if I will remove the small bump-mod.   Greetings from Belgium.

The Fender Rhodes Electric Piano / Re: How good is the Bump Mod?
« on: April 16, 2021, 02:10:36 PM »
I have to add.
There is definitely a lighter action.
But after two years, I am still not sure whether too keep the mod or to remove it.
Like some other forum members, for some reason, I just can't reach the same dynamics and bark... whatever I try with escapement or hammer throw.

I also have a Wurlitzer 200A.  The action is different.
It has a totaly different concept. It has a simplified real piano mechanism.
The Rhodes has a different concept. I guess it's just impossible to obtain the same action with it.
I think that's just the essence. It's a different instrument.  You need to work it harder. But it rewards by more pronounced dynamics and versatility in sound.

The Fender Rhodes Electric Piano / Re: How good is the Bump Mod?
« on: April 16, 2021, 02:03:06 PM »
Hi Dr Pepper.
Really interesting research.
I have an early 1975 Rhodes with hybrid hammers and flat pedestals. 
The seller-technician installed the pedestal mod.  the bump was at the edge of the pedestal.
Although it might be an improvement to earlier action, I still wasn't happy with the action.
So I started experimenting. I came up extending the pedestal and adding extra bump.
Somehow it looks a bit to what you designed... but mine being much more basics.
I just glued a piece of wood on the extension of the pedestal and added some pedestal felt.
Hope you can see the picture.
I experimented in heights and lengths.
Some of the almost reaching the measures of your design.
The one on the photo was my lowest. These are still in the midrange of my Rhodes.


If you stick your fingers in your ears, can you still hear the noise?


 :D :D :) ;)

Other Keyboards & Software Synths / Re: Homemade electric piano
« on: March 11, 2021, 06:51:22 AM »
Eager to see your progression...Respect....

The Fender Rhodes Electric Piano / Re: PLASTIC LID COVER PAINT
« on: February 18, 2017, 07:47:26 PM »
But I agree with David's main point that, unlike vintage guitar collectors, most Rhodes players don't seem at all put off by restorations or modifications.

There may be a big difference between guitars and a Rhodes.
My old Fender Jazz Bass -untouched since late 60's- is even better than a new one.
Even the pots. They work fine. No need to change anything   except for the strings.

A Rhodes  with original parts (grommets, hammertips..)  and without serious service is ...worthless.

But then I agree I would rather  keep the main components original,  in case our Rhodes would gain value over (a lot of) time.
So personally , I would rather deal with some scratches and some ripped tolex.

I  checked the speaker cables. They are OK.  Your modules just go louder and clearer, Mike. That's not a shame  ;D
I pushed the volume to 10 (and played softy). Loud, but under control.
The volume is really gradual.   At volume 10, quite a bit of hiss comes up... which I think is normal at that level.
These are good modules Mike. You may be proud.

As for the heatsinks. Yes, they are a bit deep. I also had a pair of flatter, longer sinks.
But these looked and felt better. And drilling the holes was very easy with my 10 dollar cobalt drill.
I was even able to mount them back the same way in the cabinet. But that would only leave a distance of half an inch from the grill cloth... 

The top holes were fine. The PCB is mounted on teflon spacers

Buying / Re: WTB Peterson 80W poweramp unit
« on: January 29, 2017, 05:21:25 PM »
Hello Jon, I don't have one.
But you might be interested in my new post ?

There are lots of aluminium heatsinks on Ebay.
Probably also in a size that fits even better.

I think I used this one.

But I remember considering to buy a longer heatsink (for 4 transistors) and cut them in the exact size.
That would make it very close to the original heatsink.
Oh I forgot to mention. I had to drill two more holes in the base of the sink.
Just to fit the PCB 4 mounting holes.

You installed the speakers incorrectly.  I can see that you are employing a parallel connection when they are supposed to be series.  This is why your new amps are extremely loud: Your effective load is 4 ohms instead of 16. :)  My modules should take a 4 ohm load but it is not recommended and you will probably destroy your speakers.

Hello Mike,

They used to be 32ohm speakers connected in parallel. Which makes a load of 16 Ohms per channel.
I changed them for 8 Ohm speakers which I connected serial. That should also make a load of 16 Ohms per channel.
I am pretty sure I hooked them up right, but I will check this again next week ..better safe than sorry.

Yes of course...I would not advertise a preview of just some smoke.

To be honest, I did make a small mistake in my wiring of the transistors  in one module ???
But that was just inattention of me. I was fast enough to put that right. 

What happened when I turned the switch on ?
Nothing. Except for 2 green LED bulbs lighting up on the amp modules.
This was OK. But no sound except for just one soft "click/plop"  coming out of the speakers …
I reached over to touch some keys on the keyboard and guess what ?
An F Sharp diminished or something like that … full sounding with a nice body…
I was surprised first ...and then extatic.

With a volume level at about 2 on a scale of 10 (in fact there are no figures on my volume-pot. Just an estimation).
EDIT feb 1th: there ARE figures on the volume scale. They are just small ... and I need glasses...

This speaks for itself already, doesn't it ?
No more hiss or hum at a this relatively low volume level.
This is a major difference. Turning the volume up makes the next difference: it can go incredibly loud.
No comparison with my former original amp modules. 
Without amp-distortion. 
What happens over level 5 (half of the volume-pot reach) is real overkill in my room.
At level 6  my son’s drum set is easily overruled. 
To be honest, at a level above 5, a lot of things start rattling.
EDIT feb 1th:  above level 6... but the speakers keep performing well.

This is resonance of both the instrument (especially the suitcase cabinet and components) and all kinds of things in the room.

Clean sound from the amp up to high volumes, that’s new to me.
Much cleaner and transparent than the old modules. 

I had to  readjust volume in the high pickups.
They sounded too hard and sharp.

But then, for the rest of the keyboard, sound is nicely balanced . 

The brightness and bass tuner-pots of my pre-amp seem to react more  gradual and smooth in combination with these modules. 

Is it more brilliant and clear ? Definately yes.
Is it “high-fidelity” transparent ?  No.
Not yet ?

I plugged my CD-player directly into the suitcase-input, and this does not generate  a real hi-fi sound neither.

OK, these are 12 inch guitar speakers. We can not expect Wilson-audio sound of it.
But my Silverface Twin Reverb seem to go way beyond that in terms of transparancy.

So I wonder if I chose right in buying the (vintage) Jensen CH/Mod 12-50 speakers recently.
They were definately an upgrade to my old worn-out Eminence Alnico's.
I tested two kinds of Jensen speakers (the CH/MOD and the C12N)
View my other post

With the old amp modules it didn't make that much of an difference.
That's why I chose the cheaper and lighter MOD's.
The C12N's had brighter mid's . But not all that much difference on the old modules.
On these modules it surely would have made the difference...
I am convinced that a combination of these amp modules with other speakers can raise the suitcase to a new level.

So, I will do some experimenting on speakers soon.

It’s a huge upgrade already.
It's is nice sounding. Full-body. Full control.
The dynamics are fantastic.
Such a pleasure to play the suitcase now.

I mounted them back into in the cabinet again.
As the heat-sinks are a bit deeper and shorter I mounted them on  small L-profile brackets.
I will shorten the wires soon. and solder them instead of the temporary connectors.

By the way, the amp – modules stay cool.
Even when playing very loud for some time, the sinks just get “hand-warm”.

I think this design is very mature.
Way better,  more safe,  operational and reliable than the original, that is for sure.

What did I pay for the modules ? I payed about 150 EURO for both modules.
But as far as I understand, this price could be temporary as it  is still  a kind of Beta – testing.
It didn't cost me more than having both my old Peterson Modules repaired by an amp tech.
And it was way cheaper than the alternative on the market.
(I haven’t tested these, so I can’t judge them… )

But to my opinion,  these amp modules a high-end design.
It is a new circuit that deals with  some problems of the old design and uses evolved insight and technology in an effective, musical and functional way. 
It is ready to be commercialised. I am sure it will make a lot of suitcase-owners happy.

The only thing Mike should work on ... is a simple installation manual...for  dummies like me  ;) 

OK. Thank you for the response.
The file is on my other computer. I will upload it monday or tuesday.

Not a single response? Looks like nobody is viewing this forum any more ... ???
At least...not much happening on it in general.
Or is this not interesting ?
I still wil do the post with the review soon anyway in case somebody in the future would want the information.

For Sale / Re: Fender Rhodes 7054 “Peterson” Amp Redesign Kit
« on: January 23, 2017, 04:04:38 PM »
I have already posted an "unboxing" part.

The review is coming soon...

Sorry for my English. It's not my first language.

My new 1975 suitcase – Peterson- Rhodes  is a great instrument  in very good condition.

It is “all-original”  except of course for the small parts (grommets,
hammer-tips, action mod, washers, felts..)
I intended  to keep it that way.  

But to be honest, some flaws and issues kept bothering me.
Like a lot of old suitcasesit suffered from modest volume, unwanted distortion, especially when pushing the volume, crackling noise, a bit of hum…
And of course the well-known  “muffled” suitcase sound...
OK, it’s charming in a way. But I would rather reach  that particular sound by turning my tone control
button to the left... but also be able to have some brilliance and transparency when it is turned to the right…

As I wanted to keep my suitcase original  I decided to “replace” some parts, rather than to repair or modify.
And I would keep the original components stored safely in a dry place.
Everything should be reversible.

So I replaced  the old alnico speakers for some new Jensen CH/Mod 12-50
I doubt this was a good choise. I will explain later.

I replaced the old Peterson pre-amp for a new  Vintage Vibe pre-amp
Great product, sounds like the old Peterson pre-amp, but without the noise, humm, crackling etc.

And recently I installed  the new amp modules designed by Mike

Fender Rhodes 7054 “Peterson” Amp Redesign Kit

Mike offered two things:
-              Sending just the printboards with the transistors
-              Installing  the PCB’s and transistors to my current Peterson modules (which I had to send to him)

As I wanted  to be reversible, there was only option 1.
So I ordered a pair of modules from Borish electronics.

Meanwhile I ordered a pair of Indonesian good quality heat-sinks for about
20 $, shipping included. They are a bit shorter but thicker, but look and feel very well.

The heat-sinks arrived a few days later.
Belgian Customs clearing kept the amp modules for  more than one month   :o :o >:(  tsss....

Anyway.After this month, both PCB’s arrived well, together with 4 new silicon transistors and fuses.

I  have very modest notice of electronics.
On Borishelectronics’ website the modules are called  “drop in replacement”.

This would surely be the case if  I would have sent in my old Petersons, to receive ready-made modules.
But I had to install the transistors and do some wirings.  Also I had to check  for regulating the bias and offset.  :-[
After Mike’s  first e-mail with instructions regarding this,  I concluded I  would  depend on my local amp tech.

But when the modules finally arrived,  my amp tech  went on holidays…for three weeks.  
I have been patient enough with the customs - delay,  so I decided to try it myself.

To install the transistors to the heatsink, well there was Youtube and Google  ;D.
It looked pretty obvious, so I felt rather confident about that.
The wiring made me doubt a bit. I was not sure about 2 wires.  (only 4 wires, one wire is ommitted in this design)

But I managed to install them.

I was very eager to test my modules.
I don’t have a “variac” like Mike suggested (who does anyway?) so I plugged
them directly into the power section of the suitcase…with speakers connected of course.

You can see the new modules attached to (temporary long wires  connected to) the Power supply.
And in front the old Peterson modules.

I kept the power switch between my shaky fingers in case  the modules would show up as smoke generators  ;)
What was / is  the result ?
Just one short sound ? With some visual firework effects ?
Or will I finally  make my point and just describe the qualities of the amp modules ?

 That is for my next post…if you still would want to read it. It is already
a lot of writing for me and reading for you ::)

This was the UNBOXING part. Next is the review.  Hope to see you back...

What a sound ...and great playing.
My early 1975 suitcase may need some tweaking for this...
Or perhaps it doesn't have the potential at all ?

Preamps, Modifications & Upgrades / Re: Suitcase replacement speakers
« on: October 09, 2016, 04:56:39 PM »
Looks great. Sound samples are pretty convincing.
But with its heavy magnet, doesn't it offer too much from the small 40W amps in the suitcase ?
And it weighs 10.6 Lbs. The Jensen Mod only 4.05 Lbs
Jensen also costs less than half the Webers. It counts for 4 speakers...

The suitcase cabinet may not be conducive to bass response as it is pretty shallow.  There's a reason why bass cabinets are at least twice as deep.
My old Fender Bassman Ten provides nice bass and is even more shallow.
I think suitcase cabinets suffer more from "boomy" bass than real production of low end frequencies.
I guess cabinet/case construction plays a big role in this.
Unlike  real hifi speakers there has been very modest attention to reducing the Q-factor like with bracings, damping materials...
I guess this would have made the cabinet un-transportable.
And damping material in a cabinet with an amplifier ?  ???

My self made DIY 3way hifi speakers weigh 120Lbs ...each.
And they are only 3ft high...lead bitumen between two layers of mdf and stuff... 


Preamps, Modifications & Upgrades / Re: Suitcase replacement speakers
« on: October 08, 2016, 06:09:28 PM »
OK.  I had the opportunity to try them both.
And guess what ?  Still in doubt. Although.
The C12N  definately produces brighter mid and high, something this Peterson suitcase amp/cabinet could use.
But in a way that I feel the need to readjust volume levels for some pickups in the mid-high. And I am not looking to touch the voicing of my instrument.
The bass is somewhat less  than the CH/MOD. It is still OK, but I had to turn up the concentric knob for extra bass. This makes it to my tasyte more boomy and less articulate than the CH/MOD. has a bigger magnet than the CH-MOD (always thought that this would guarantee better bass definition).
So for the moment I lean a little towards the less expensive CH/Mod.
I like the sound with the bass knob  about half way (still accurate and articulate with an nice body) and the treble knob all the way up.
From the player position it would have been nice to still have some more transparancy and brilliance...but then I realise that it's a suitcase,
with the speakers at knee-height. If I bring my ear under the keys, brilliance is sufficient
And, oh, the CH/Mod is about 2Lbs lighter than the C12N. For what it's worth.

Preamps, Modifications & Upgrades / Re: Suitcase replacement speakers
« on: October 03, 2016, 05:09:12 PM »
Thanks Ben. This is actually what I suspect.
I will soon have the opportunity to check them out both !
According to a friend (guitar player) who uses both speakers, the CH/mod version also  has pretty clear mid/highs.
I will let everybody know the results.

Preamps, Modifications & Upgrades / Re: Suitcase replacement speakers
« on: September 27, 2016, 06:30:13 PM »
This is a comparison I found of the Jensen mod 12-50  and the C12N
RED is the C12N
Blue the MOD 12-50


Both do not stand out for bass performance. Although this should be OK ?
The MOD 12-50 doing slightly better than the C12N (about 5db at 50Hz)
In the mid-range the C12N is obviously more aggressive. In the highs they seem about equal.
The MOD 12-50 being the better of the 2 according to this graph ?

Preamps, Modifications & Upgrades / Re: Suitcase replacement speakers
« on: September 27, 2016, 12:44:36 PM »
I . In my opinion, the highs are amazing and the mids are nice, but it really lacks in the lower bass. I personally liked the original stock speakers better

OK thank you for this information. Very useful.
On my rhodes now the bass (flat) knob is turned entirely to the left. Because it's just too bassy / boomy.
The treble knob at the other hand is turned entirely to the right.
That's why I was heading towards this kind of speaker.
But there is a difference between exact, steady and powerful lows  versus  some loose boomy lows, I understand.

Eminence makes many excellent musical-instrument speakers--well worth checking out, and they're even made in the USA.

I wil certainly look at these too.  Being made in the USA is perhaps not a great advantage to me...I live in Europe.  ;) 
But from the quality point of view, it certainly is...

Preamps, Modifications & Upgrades / Suitcase replacement speakers
« on: September 26, 2016, 04:40:35 PM »
My old 1975 suitcase (Peterson amp) still has its original eminence alnico 12 inch speakers.
Nice vintage sound, although I think there is room for some improvement.
My tech (specialist amp repairman) indicates that new speakers or new cones may result in much better mids and highs.
I found the Jensen MOD12-50 at a very reasonable price.
However, according to the specs and sound samples on the Jensen website, the slightly more expensive (but stille affordable) C12N  should produce more articulate mids and highs...what an old suitcase may be missing a bit....


Hello Art.
Seems like nobody is answering you.
Hope this is not too late.
Might be that we don't have enough information for an answer.
Do you have the amp (Janus amp or Peterson) or also the entire amp with cabinet ?
In both cases the EP is attached to the amp through the pre-amp.
In case of a (older) Peterson the 4 pin cable provides the pre-amp of current.
With the newer Janus 1 amp a 5 pin cable does the thing.

I have a vintage vibe pre-amp for my old 1975 suitcase. It's great.
It sounds even better than the original Peterson pre-amp...with much less noise, hisss...
Well worth the investment if you ask me.

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