Orange inspired project

[TubeGeek]

I am going to build myself an amp based on the Orange/Matamp tone. 

Any experts out there that have been down this road before and could offer me some insight?


I want thick distortion with sustain.  This link explains what I am going for:  Sleep - Dopesmoker


I have ordered Heyboer Hiwatt 50W OT and PT for this project.  I also have a hiwatt size chassis and maple cabinet built that will work perfect.


Any info on this would be greatly appreciated.  I am in the beginning stages of collecting info and putting a plan together (layout).


Right now I am thinking of building from the orange overdrive series, which adds a master volume to the early 70's design. See schematic.


TG

[Glennjeff]

Wow,
Listening to that music got me stoned. 
Hope you chronic(le) the build.

[jojokeo]

I am going to build myself an amp based on the Orange/Matamp tone. 

Any info on this would be greatly appreciated.

I'm almost positive that sound/tone is not strictly from a tube amp w/out help from a pedal? I've got a pedal that does that easily. You try to do that by building a "specialized" tube amp and a one trick pony you will get and still very likely not reach that place you desire? Just my 2cents trying to save you money, time, & the trouble...

[VMS]

I think Sleep used Green amps, which might be based on matamp gt series amps.

www.youtube.com/watch?v=VlnWpzo2ZcM


Some links to Matamp schematics and info on green amps:

http://el34world.com/charts/Schematics/files/_Miscellaneous/Matamp_1973GT-120.jpg

http://el34world.com/charts/Schematics/files/_Miscellaneous/Matamp1973GT-120Schematic.gif

http://www.nicosonic.com/1st_tech_article

http://www.planetoftheamps.com/amp-reviews.html

[TubeGeek]

I am going to build myself an amp based on the Orange/Matamp tone. 

Any info on this would be greatly appreciated.

I'm almost positive that sound/tone is not strictly from a tube amp w/out help from a pedal? I've got a pedal that does that easily. You try to do that by building a "specialized" tube amp and a one trick pony you will get and still very likely not reach that place you desire? Just my 2cents trying to save you money, time, & the trouble...

Yeah I hear what you're saying but I believe most of the tone is set by the amplifier and a pedal is used to add sustain and boost.  I already have 90% of the parts in my shop to build the amp so it's not a huge expense up front.  The only real expense was the transformers. 


This video demonstrates the vintage orange tone quite well.


https://www.youtube.com/watch?v=EcFCbzgBuMs

[TubeGeek]

I think Sleep used Green amps, which might be based on matamp gt series amps.

www.youtube.com/watch?v=VlnWpzo2ZcM


Some links to Matamp schematics and info on green amps:

http://el34world.com/charts/Schematics/files/_Miscellaneous/Matamp_1973GT-120.jpg

http://el34world.com/charts/Schematics/files/_Miscellaneous/Matamp1973GT-120Schematic.gif

http://www.nicosonic.com/1st_tech_article

http://www.planetoftheamps.com/amp-reviews.html

Wow that is the clearest matamp gt120 schematic I have seen, thanks for the heads up!

[TubeGeek]

Several years ago I had a Matamp series 2000 come across my bench.  I immediately fell in love with it.  Something about the quality of construction and different way of doing things appealed to me.


The Series 2000 is not the high gain monster though, it is more of a bluesy type tone most well known to be used by Peter Green's Fleetwood Mac - Albatross.


What intrigues me is the circuitry design.  The FAC control, where it is inserted. The Matamp's have a cool design too. Matamp and Orange are pretty much the same thing to me.


I am thinking the way the cap switches are in these circuits play a big role in their tone(of course).  I have not analyzed it yet, not sure if I am that smart.   I am hoping some of the smarter dudes here can explain the circuit so it makes sense.  I attached a matamp schematic to reference what I am talking about.

[TubeGeek]

Another video that nails the tone I am seeking:


https://www.youtube.com/watch?v=KKb42Otbz5k

[VMS]

If I'm not mistaken, this is the thread for that amp:

http://music-electronics-forum.com/t26551-3/#post320711

[HommeMarrBuckley]

Not an expert at all but definitely interested in this one TG.   A while back I was checking out the Matamp Gt 100.  According to many this schematic was pretty accurate.  Not sure with which amp you're headed.
http://vintageamps.com/plexiboard/viewtopic.php?f=4&t=99260
I emailed a guy named John Mcneece who seems to know this circuit quite well.  Really interesting and nice guy---was browsing his site and came across Fender 400PS (nuts)
In regards to the GT he said
"The original GT was almost the same as the orange graphic, the OR has no second click switch, the EQ and FAC swap positions, plus a few slight component changes.
The Mats and oranges ran at 515-540 VDC on the plates. This affects headroom. Also it is rough on tubes. Marshall types usually end up at about 480VDC,
Their output transformers have a winding ratio that is different, extended frequency response, very hi-fi. The downside of this frequency response is a scary plate impedance that is very unkind to tubes. A modern EL34 will not last long unless the amp is played at jazz volumes. There are fixes for this but the amp will not sound have the 100% "Mat sound" so back to square one. "
I checked out Electric Transformers but were pricey and with this felt out of my realm--think I had trouble finding one of the rotary switches as well.  Planet of the amps site is pretty cool too.  I have seen your other builds so probably much easier for you to do.  Anxious to see what you produce.  When I want to go through walls, I dig some Pike, too.  High school and twenties--just fell in love with drop C and exotic tuning sound.  It came from the desert....Ahhh memories.

[HommeMarrBuckley]

Almost forgot and maybe off topic, but Steve's Sceptre or T-100 can probably achieve that sound as well.

[jojokeo]

sorry I might have forgot to take into account the low tuning guitars contributing to that sound also. I was just looking at the schem briefly and going by experience.

[shooter]

The Mats and oranges ran at 515-540 VDC on the plates. This affects headroom. Also it is rough on tubes. Marshall types usually end up at about 480VDC

Is this how they're claiming "50W version" on the schematic.  I have a similar build done as a working prototype, my plate is at 430 and cathode R is 270 and I'm idling right at 25W/tube, but at the speaker the amps pwr is 24ish watts, which I would expect.  I'm having a hard time seeing 50W at the speaker without my tubes melting.  Can someone clear up my mud brain?

thanks

[VMS]

Mullard datasheet page 3 says Pout should be near 40 watts given that the Raa is the same:

http://frank.pocnet.net/sheets/129/e/EL34.pdf

[shooter]

That's the datasheet I'm working from, but initially I was closer to the 3.5k Ra-a (B+370ish) but I changed taps and since B+ is closer to the 450 datasheet, I didn't use a 16ohm speaker to change my reflected impedance closer to 6.5k!!  Gotta do some measuring anyway so I'll do it with a 16ohm speaker n see if that gets me closer

thanks!

[Colas LeGrippa]

on the orange schems , C20 shows the same value as C19 which is 4700pF, I think it should be 10,000pF .


Colas

[TubeGeek]

Looking over these designs I see something new to me:


The PT secondary HV centre tap connects to the middle +/- of the first filter cap node.  I am thinking this raises the B+ voltage higher than with just the 360-0-360 Pt specs?


This could be where the higher than typical B+ comes from, correct?

[shooter]

Ya, I am Cathode biased, I was referencing the Matamp schematic that said 50W model, and that is cathode biased also.  That's what got me wondering how it's 50W - at the speaker, not as a room heater.

[TubeGeek]

Another new thing to me is the depth, FAC controls. I am trying to wrap my brain around the mat amp design, it confusing to me.  I have a "mud brain" as shooter puts it!


They seem to me to be a way of filtering the signal.


The placement of these controls differs between them too.
Early matamp's have a more complex network that is inserted right at the input before v1a grid input and off the plate of v1a is another "fac" control.  The switching here is confusing as hell to me.


Orange only has the fac control which is inserted off the plate of v1b.


My questions are how much does this affect the tone and I wonder what I am going to prefer?  I guess I will have to decide to build it and try them out and then I'll know what my ears like.  I'll probably begin with building the orange graphic mkII with a master volume as my foundation and experiment from there.

[TubeGeek]

Ya, I am Cathode biased, I was referencing the Matamp schematic that said 50W model, and that is cathode biased also.  That's what got me wondering how it's 50W - at the speaker, not as a room heater.

Oh my bad.  You were referencing the series 2000.  I've got three of four schematics in front of me at the moment, it's getting a little confusing 


I had that amp on bench, I'd say it's more of a 20W model for sure.

[VMS]

To add to your confusement, these are probably somewhat proven builds:

for matamp I would go with schematic on this post:

http://music-electronics-forum.com/t38447-2/#post372170

and for orange with schematic on this weber kit:

https://taweber.powweb.com/store/kits_60b.htm#6o100

[shooter]

how much does this affect the tone and I wonder what I am going to prefer?

I think that's the point of the circuit, to give "lots?" of tonal choices.  I knew I seen that circuit, here's the link
http://home.comcast.net/~seluckey/amps/dual_lite/Dual%20Lite.pdf

Good luck n thanks for clearing up the 20/40watt thing, so the amp schematic should read "50W heater, 20W amp"

[darryl]

The PT secondary HV centre tap connects to the middle +/- of the first filter cap node.  I am thinking this raises the B+ voltage higher than with just the 360-0-360 Pt specs?

The DC voltage at the transformer centre tap is exactly 50% of B+, so this circuit is a simple way to provide a reference for the junction of the series filter caps. In amplifier designs where the screen voltage is required to be 50% of the plate voltage, this centre tap arrangement is a very effective way of generating the screen supply.

The diode bridge in the above drawing is incorrect - the bridge needs to be rotated 90 degrees counter clockwise.

[TubeGeek]

The PT secondary HV centre tap connects to the middle +/- of the first filter cap node.  I am thinking this raises the B+ voltage higher than with just the 360-0-360 Pt specs?

The DC voltage at the transformer centre tap is exactly 50% of B+, so this circuit is a simple way to provide a reference for the junction of the series filter caps. In amplifier designs where the screen voltage is required to be 50% of the plate voltage, this centre tap arrangement is a very effective way of generating the screen supply.

The diode bridge in the above drawing is incorrect - the bridge needs to be rotated 90 degrees counter clockwise.

Makes sense with the CT. Learned something new.  Seems obvious now.


Yes i saw the rectifier was incorrect.  This was pointed out in another forum as well, which may be where i found it.


I have been staring at these schematics this weekend in an effort to clear up any mud.  Im looking closer at Weber's design now.  Looks like they did all the work for me. Between all the info i have, i have got plenty to work from.  Ill post more as i get to it.

[Glennjeff]

This circuit is different enough from "the usual" stuff to be interesting.
The tone is great for "that" style of metal.
I for one will watch with interest.

Is it the triple ganged switch across stage 1 and 2 that is doing your head in. Switches will do that

That switch appears to be providing a range of treble and bass contours to the preamp.

In the first two positions it is applying negative feedback that has bass emphasis, thereby cutting bass / low mid response.
The second position also puts a bright capacitor onto the gain pot.

In the third position the switch does nothing new.

In the fourth position it is putting a bright capacitor across the gain pot.


All the best
Glenn

[TubeGeek]

This circuit is different enough from "the usual" stuff to be interesting.
The tone is great for "that" style of metal.
I for one will watch with interest.

Is it the triple ganged switch across stage 1 and 2 that is doing your head in. Switches will do that

That switch appears to be providing a range of treble and bass contours to the preamp.

In the first two positions it is applying negative feedback that has bass emphasis, thereby cutting bass / low mid response.
The second position also puts a bright capacitor onto the gain pot.

In the third position the switch does nothing new.

In the fourth position it is putting a bright capacitor across the gain pot.


All the best
Glenn

Switches have always caused me grief. 


This tone may not be everyone's cup o tea, but thats doesn't matter to me.  I like the tone enough to build one so when i feel like playing loud with lots of thick distortion, I can do it anytime i want I enjoy playing this kind of riffage while I record it on my looper and then sit behind the drums and bang away for a while.  It is a great stress reliever after a long day at work,  i have my looper setup with multpile outputs so i can also have a bass loop playing to its own output, into a bass amp.  Its a one man band setup and only i hear how bad i play 

[Glennjeff]

The tone actually grows on you the more you listen to it.

Sounds like you've got a great "fun with my instruments" setup.
Drums are the best for de-stressing applications. 

[MFowler]

I built this Orange amp quite a few years ago.

[lego4040]

Damn that green Matamp in reply 8 is the shit. Have you ever listened to the band "The Storm"? If not, Its like vintage Sabbath on Roids. Another amp to go on the Bucket build list

[TubeGeek]

I ordered a pair of Celestion G12H-75 Creamback speakers for this project.


That means I will have three sets to choose from when it is done…Vintage 30's, Vintage Fane's and the Creambacks. 


I am going with a 2x12" cabinet, covered in orange tolex with white small cane grill cloth.


I have a fairly clear direction on the circuit now.  I've been studying and pondering it for a week or two now.  It's going to be based on the Orange OR80/120, Weber 6O100 and experiments with ideas from the Matamp/Electric schematic.  Hopefully I'll find what I am looking for between them after some noodling.

[MFowler]

I built this Orange amp quite a few years ago.

Thanks for sharing.


Looks like a nice circuit, does it nail this kind of tone?

Very versatile amp due to the ability to switch from Class A cathode bias 30w or Class AB fixed bias 50w.  I guess a person would need to find a good quality audio of this amp to compare with other Orange offerings.  Mine has plenty of gain and is loud.

[jojokeo]

Nice work Fowler, but what's the reasoning with all the pots being dual ganged like that (safety/redundancy?)? On some it would put them in parallel so they would be 1/2 the value of what the schem possibly? (I can't see the schem as it's too small).

[lego4040]

   How did this amp turn out? Its been a few months. Also If I was intersested in building that Series 2000 for that Peter Green clean sound which schematic/layout would be the best to follow?

[TubeGeek]

  How did this amp turn out? Its been a few months. Also If I was intersested in building that Series 2000 for that Peter Green clean sound which schematic/layout would be the best to follow?

I have everything I need to build the amp but no time to do it. Now that the weather is getting nicer where I live, I will be spending my free time in the mountains camping.


The amp will get built just not sure when I will be inspired.  I'll update when I do get to it.

[TubeGeek]

Summer is ending so I am getting back to working on projects. 


I have clear coated the maple head cabinet and have worked out the details on the front faceplate and control plate.


Next step will be to mark the chassis layout and drill.


This weekend I am planning to tolex the 2x12 cabinet and speaker baffle.


Following that I will be working out the final details on the circuit I am building.  I have 3 or 4 schematics to look at.


Thought I would update on this project as I go...

[TubeGeek]

I also painted the transformers

[lego4040]

Oh that is nice sweet Cab. That's gonna be a heavy cabinet to lug around too, where did you score nice maple like that? Great grain and lining up at the dove tails.

[HommeMarrBuckley]

What transformers did you go with?
Are you using one schematic and veering off here and there?
Where you source the chassis and size?
Sorry for being nosey, just curious.
Looking pretty rad.  Nice

[TubeGeek]

Oh that is nice sweet Cab. That's gonna be a heavy cabinet to lug around too, where did you score nice maple like that? Great grain and lining up at the dove tails.

Thanks!  I found the spalted maple wood at my local lumber store.  My buddy did the wood work for me. 


I don't plan on taking the cabinet around much, it'll pretty much stay in my studio/shop.

[TubeGeek]

What transformers did you go with?
Are you using one schematic and veering off here and there?
Where you source the chassis and size?
Sorry for being nosey, just curious.
Looking pretty rad.  Nice

I chose to go with Heyboer's 50W Hiwatt PT and OT and a Hammond choke (reactor as Hammond says on it)


I am trying to iron out the circuit details but at the moment I am pretty much going with the Weber 6O100 circuit.  It is close to what the original circuit is, with an added mid control and a presence control.  I will be experimenting with different values and may not add the mid and presence controls.  That's why I had two faceplates made up, so I can experiment and see what I prefer.  I may also experiment with placement of the fac drive controls(matamp style). My goal is to build the original orange circuit with a master volume, this would be the overdrive series.  Weber has done most the work for me, I just need to build it and tweak to my liking.


The chassis size was sourced from a Hiwatt Custom 50 I built years ago.  At the time I built the hiwatt, I had 3 of these chassis made up.  I used one for the hiwatt, one for an ac30 and now this last one for the orange.

[lego4040]

That faceplate is incredible, would you mind telling us your source? I need a faceplate for my 5G9 build. My Combo cab came in last week but I had to send back, mix up in their shipping department.

[TubeGeek]

That faceplate is incredible, would you mind telling us your source? I need a faceplate for my 5G9 build. My Combo cab came in last week but I had to send back, mix up in their shipping department.

I take my ideas to a local laser engraver where we sit down and design the layout in corel draw and then laser etch the lamacoid product with the color I choose.


On a DIY project like this one I like to have the faceplate made up before I drill the chassis holes.  It makes it a little easier to get the holes lined up properly.


http://www.miragelaserdesigns.com/index.html


We are in Alberta Canada, not sure if that'll work for you but he does ship his stuff all around the world.

[Fresh_Start]

The DC coupled cathodyne phase inverters of the old Matamp and Orange amps have me confused. The Weber schematic above shows a "normal" AC coupled cathodyne with a grid return resistor connected to the bottom of a small cathode basing resistor. However, the old Matamp and Orange schematics simply show 100K cathode and anode resistors on the PI with the grid connected directly to the preceding stage's plate. No grid stopper and I don't understand how the PI triode is biased.

Help?

Chip

P.S.  Forgive me if this seems off topic.

[TubeGeek]

The DC coupled cathodyne phase inverters of the old Matamp an Orange amps have me confused. The Weber schematic above shows a "normal" AC coupled cathodyne with a grid return resistor connected to the bottom of a small cathode basing resistor. However, the old Matamp and Orange schematics simply show 100K cathode and anode resistors on the PI with the grid connected directly to the preceding stage's plate. No grid stopper and I don't understand how the PI triode is biased.

Help?

Chip

P.S.  Forgive me if this seems off topic.

I am glad you asked! I have the same question.

[Fresh_Start]

Merlin has a nice explanation of cathodyne phase inverters, but it doesn't cover this variant at all.
http://www.valvewizard.co.uk/cathodyne.html

I don't remember seeing this approach before.

Cheers,
Chip

[sluckey]

Merlin has a nice explanation of cathodyne phase inverters, but it doesn't cover this variant at all.

Look at his page on the dc cathode follower. It's the same thing. Well, it is if you split the cathode resistor, putting half on the plate, half on the cathode.

     http://www.valvewizard.co.uk/dccf.html

That dc cathodyne has been around a long time. A couple years ago I converted a 1954 Rockola jukebox amp to guitar that had that PI. I kept the PI and PA and just put an AB763 preamp in front.

     http://home.comcast.net/~seluckey/amps/rocky/rocky.pdf

EDIT... The Magnatone 260 and 280A guitar amps both use that same PI. The 260 schematic is too big to post but here's the 280A...

     http://magnatoneamps.com/schematics/magnatone_280a.pdf

[TubeGeek]

The long overdue project continues….


This project gets put on the shelf when I have requests to build for others.  It's been a while now but I finally have a weekend free of other's amp work so onto this project for a few days.


My goal this weekend is to get the metal chassis drilled and primed and possibly the first coat of paint completed.  My idea is to paint the outside and inside of the chassis with a hemi orange enamel spray paint.


I have been working on the chassis layout and this is what i have come up with.  I need to ask some opinions on the orientation of the output transformer.  Which way would you face the OT laminations? vertical or horizontal? Or would it even make a difference?


My thinking is to mount the OT with the laminations going horizontally because I think there may be less "magnetic flux" or force-fields going directly into the preamp tube area (top right of the pic), if it were to be mounted with the laminations going vertical.  Horizontal concerns me because they are in the same direction of the PT. Or are they far enough apart  that it won't matter?
 

[TubeGeek]

Here is the chassis inside layout so far

[sluckey]

Your layout resembles a Sunn. Maybe this will give you some ideas. I can post a gut shot too if this looks interesting...

[TubeGeek]

Judging by the sunn I doubt I will have to be concerned with the OT placement. Thx.