Show us your guts! (Express Content)

[NuSkoolTone]

Before I took the Express back, I snapped some pics. When I spoke to the Boogie Tech, he said as long as I wasn't an idiot, I wouldn't void the warranty opening it up when we spoke about possible mods. (They REALLY just don't want anything to do with mods, the Hollywood mod is considered a fluke)

So here they are enjoy! (Soundclick mashed down the size a bit, so if someone has the upload space, I can send them the full size pics)

http://www.soundclick.com/members/default.cfm?member=nuskooltone&content=photos&albumid=1942&id=30620

Share us yours! Eventually I'll do the same with my recently acquired F-50.

I'd really like to talk about some basic mods for this amp. Particualrly the contour section. If I can get the high end sizzle (The Express had it too, it's just the design) out of contour mode this amp would be perfect me thinks.

About the pics:

-There is a pic that shows they are actually using 2 Carbon Comp resistors in the pre, so perhaps that validates there's something to them!

-Another pic shows the power tube board. When I spoke to Boogie, they said looking from the back the LEFT Tube is used for 5W mode. So while they said they recommend re-tubing every two years, those that play alot in 5W mode may want to consider rotating the two tubes so they wear evenly. At least I think that would make sense!

-There is a close up of the contour section to see what may be different.

-There is a picture of the whole chassis, and a composite of all the close ups matched up best I could to be one picture. However the size is reduced on soundclick, so I'm not sure how interesting it is. Perhaps someone else can host it?

 

[Charlie]

It's kinda weird that mesa mounts their tubes sockets directly to the PCB like that. Do they build all of their amps that way? Other than that I love the way they construct their amps... with flying leads and all.

 

[Boogiebabies]

Mesa has been using CC's in the Lone Star and RK II for the clean channels. It's awesome. It looks like a typical Mesa amp made in the same vain for about 20+ years. The contour section is nothing more than a graphic EQ with fixed inductor, capacitor and resistor values that basically give the amp the classis V shape, without the faders. The circuit boards in the current Mesa's all have the same look. They are mass produced in larger sheets and then snapped off.

 

[NuSkoolTone]

Wow. For some reason I thought there'd be more interest than this! Is this considered taboo or does no one care?

 

[Dutchman]

I looked but didn't reply. Thanks for taking the photo's I've really got bad GAS for a LSS or a 25:5 Express. I'm going to have to make the 5 hour drive to try them out.
Photo's like these are very helpful.

As far as the PCB's many other amp manufactures that offer less options use PCB's also so it should not shock anyone or turn anyone away.

 

[Charlie]

I looked but didn't reply. Thanks for taking the photo's I've really got bad GAS for a LSS or a 25:5 Express. I'm going to have to make the 5 hour drive to try them out.
Photo's like these are very helpful.

As far as the PCB's many other amp manufactures that offer less options use PCB's also so it should not shock anyone or turn anyone away.

The PCB's don't bother me it's just that I heard that mounting tube sockets directly to a board like that is bad. But what the hell do I know I'm not an electrical engineer or anything.

 

[Elpelotero]

it's so tiny!

 

[Dutchman]

DOPEMAN* Posted: Fri Feb 23, 2007 8:07 am Post subject:

--------------------------------------------------------------------------------

Dutchman wrote:
I looked but didn't reply. Thanks for taking the photo's I've really got bad GAS for a LSS or a 25:5 Express. I'm going to have to make the 5 hour drive to try them out.
Photo's like these are very helpful.

As far as the PCB's many other amp manufactures that offer less options use PCB's also so it should not shock anyone or turn anyone away.


The PCB's don't bother me it's just that I heard that mounting tube sockets directly to a board like that is bad. But what the hell do I know I'm not an electrical engineer or anything.

When tubes where first attached to the boards the heat would effect the board and cause troubles after a while.
I have not heard of this type of PCB disintegration for quite a while.
PCB's are commonly found in Soldano's/Diezels/Fuchs and many other "Boutique " high dollar amps.
Personally I cannot tell if an amp is PTP or PCB without opening the cabinet up. Of course 30+ years of Rock and Roll may have had some effect on that
I'm not an EE either but I did sleep in the parking lot of a Holiday Inn a couple of times. :twisted:

 

[parsky1]

Whether current is traveling through a PCB trace or a wire it really doesn't matter. Most of the current I believe travels on the outside of the wire anyways. Although I believe this is only true for an AC signal... which is what your audio signal would be. DC travels throughout the whole wire, but the only DC signals in your amp are going to be power, and switching logic lines.

 

[Boogiebabies]

Mesa has been mounting tube sockets to the PCB since the MK I.
If every amp manufacturer for the last 50 years has been using a Phenolic power tube socket, I do not see why a phenolic preamp tube socket would fare any worse. They dont see the heat or the voltage of the power tubes. Mesa uses the highest quality Belton sockets and shields.
The only difference in older Mesa's was the preamp tube socket was usually ceramic and had mounting screws to the chassis. Even the 92 Dual Recifier used PCB mounted sockets with plastic standoff's to hold the PCB. Every time you put a preamp tube in, you feel the board flex. Maybe it's a good thing to leave a small amount of give for the tube Gorilla's of the world. The Belton socket is a much better design. It not only secures the tube with solder joints, but tabs as well. If you guys think Mesa is bad, take a look at an Engl or a Bogner. They look like they are ready to mount a dual core processor. The Soldano flagship, the SLO 100 has chassis mounted pre and power sockets and the circuit board uses enormous 2 oz. copper traces with short signal paths and flying leads. It's IMO the most bullet proof design you can probably find.
You don't need to look at the design from an EE's view. You have to look at it from a CAD point of view and use what is the easiest, commonly used part and sadly, in some cases the cheapest. Mesa however, still hand draws there circuits, so what you see if Randall Smith's artwork.
He even leaves small messages on them if you know where to look.

 

[Melodyman]

Mesa has been mounting tube sockets to the PCB since the MK I.
If every amp manufacturer for the last 50 years has been using a Phenolic power tube socket, I do not see why a phenolic preamp tube socket would fare any worse. They dont see the heat or the voltage of the power tubes. Mesa uses the highest quality Belton sockets and shields.
The only difference in older Mesa's was the preamp tube socket was usually ceramic and had mounting screws to the chassis. Even the 92 Dual Recifier used PCB mounted sockets with plastic standoff's to hold the PCB. Every time you put a preamp tube in, you feel the board flex. Maybe it's a good thing to leave a small amount of give for the tube Gorilla's of the world. The Belton socket is a much better design. It not only secures the tube with solder joints, but tabs as well. If you guys think Mesa is bad, take a look at an Engl or a Bogner. They look like they are ready to mount a dual core processor. The Soldano flagship, the SLO 100 has chassis mounted pre and power sockets and the circuit board uses enormous 2 oz. copper traces with short signal paths and flying leads. It's IMO the most bullet proof design you can probably find.
You don't need to look at the design from an EE's view. You have to look at it from a CAD point of view and use what is the easiest, commonly used part and sadly, in some cases the cheapest. Mesa however, still hand draws there circuits, so what you see if Randall Smith's artwork.
He even leaves small messages on them if you know where to look.

Engl I can understand, what's wrong with Bogner? The build doesn't look any worse than Mesa and in some instances better.

They use shock mount screws to secure the PCB instead of plastic tabs.

Bogner still uses actual tube sockets for the preamp tubes, on modern Mesa's the preamp tubes look like they sink right into the PCB itself.

Bogner's transformers look beefier than what I see on modern Mesa's as well.

Bogner's PCB's don't look like they were made from a wave soldering machine in big sheets and then broken off either.

Older Mesa's is a different story, I'm not comparing those.

I'm interested to hear you comments

 

[NuSkoolTone]

Mesa has been using CC's in the Lone Star and RK II for the clean channels. It's awesome. It looks like a typical Mesa amp made in the same vain for about 20+ years. The contour section is nothing more than a graphic EQ with fixed inductor, capacitor and resistor values that basically give the amp the classis V shape, without the faders. The circuit boards in the current Mesa's all have the same look. They are mass produced in larger sheets and then snapped off.

BB, do you have any insight on how to mod this section? I'd LOVE to just swap a cap (If that's all that's involved) and tame the highs in contour mode a hair. Even better if I could put it to a push-pull pot. Sort of like the pull bright on the clean channel.

 

[siggy14]

Are the power amp tubes attaced to the PCB? I cant make it out i only see the pre amp tubes.

It doesnt hurt to mount pre amp tubes to PCB, they generate very little heat compared to output tubes. The only negative side is if it is a cheap board and breaks easy. I am always cautious when installing my preamp tubes on any amp, most every amp I have owned PCB mounts them.

Here are my guts from my 1992 dual rec, notice the power tubes are not mounted to the board.

http://good-times.webshots.com/photo/2204630590060755923kJEDZu

 

[oz_mike]

Gotta stick up for Bogner here,...

There construction technique and the quality of their parts is second to none. Ultra-low dissipation Wima metallized polyester and polypropelyne. Each type is chosen for a specific application. It's not haphazard. Silver mica caps.

In the newer amps, they've mounted their power tubes to the PCBs, but they've addressed the main concern (heat) by using power tube sockets with 1 1/2 inch legs so that there's enough room for air circulation. And the PCB itself is a work of art. VERY thick (3/24), re-inforced, through hole, well spaced out. Some of their amps use PCB mount pots (another 'no-no'), but they're the chunkiest pots I've ever seen: full-size, 24mm pots with huge brass shaft protectors.

What I love about Bogner is that they don't follow trends when it comes to how to build an amp. They think creatively about construction technique and component choice to deliver the absolute best, regardless of what the collective wisdom of 'experts' say.

 

[Boogiebabies]

Mesa has been mounting tube sockets to the PCB since the MK I.
If every amp manufacturer for the last 50 years has been using a Phenolic power tube socket, I do not see why a phenolic preamp tube socket would fare any worse. They dont see the heat or the voltage of the power tubes. Mesa uses the highest quality Belton sockets and shields.
The only difference in older Mesa's was the preamp tube socket was usually ceramic and had mounting screws to the chassis. Even the 92 Dual Recifier used PCB mounted sockets with plastic standoff's to hold the PCB. Every time you put a preamp tube in, you feel the board flex. Maybe it's a good thing to leave a small amount of give for the tube Gorilla's of the world. The Belton socket is a much better design. It not only secures the tube with solder joints, but tabs as well. If you guys think Mesa is bad, take a look at an Engl or a Bogner. They look like they are ready to mount a dual core processor. The Soldano flagship, the SLO 100 has chassis mounted pre and power sockets and the circuit board uses enormous 2 oz. copper traces with short signal paths and flying leads. It's IMO the most bullet proof design you can probably find.
You don't need to look at the design from an EE's view. You have to look at it from a CAD point of view and use what is the easiest, commonly used part and sadly, in some cases the cheapest. Mesa however, still hand draws there circuits, so what you see if Randall Smith's artwork.
He even leaves small messages on them if you know where to look.

Engl I can understand, what's wrong with Bogner? The build doesn't look any worse than Mesa and in some instances better.

They use shock mount screws to secure the PCB instead of plastic tabs.

Bogner still uses actual tube sockets for the preamp tubes, on modern Mesa's the preamp tubes look like they sink right into the PCB itself.

Bogner's transformers look beefier than what I see on modern Mesa's as well.

Bogner's PCB's don't look like they were made from a wave soldering machine in big sheets and then broken off either.

Older Mesa's is a different story, I'm not comparing those.

I'm interested to hear you comments

This is the Boogie Board. The Bogner board is over at HC.

If you read the post, it is basically ragging on all amps made with modern PCB's. When you get to stare down the guts of a Shiva, you may change your posistion. Rivera, THD, Diezel, Peavey, Carvin, Marshall, Fender and just about any other mass produced amp will have them. It's the design, integrity and quality of each integral component that make a goo PCB amp. The SLO 100 is well above industry standard and is used in my example. Granted, it's really just a two channel amp. As far as a transformer looking "Beefy", an amp designer can build or design a transformer for a specific impedence or a sonic variable. Just because it's "Beefy" does not make it better or worse. It is designed the way Rheinhold wanted it to. It has a specific load, winding, magnetisim and lamination thickness. Now a large transformer today fails in comparision to a 1951 Stromber Carlson PA with a lamination stack of 5 inches. One mans beef, is another mans jerky. O.K., back to PCB's. you cannot doubt that Randall Smith, Rheinhold Bogner, Peter Diezel and Horst Langer are not geniuses, but when you start seeing ribbon cables in amps, you have to wonder how far the progress is going to go. Fundamentally, if the design is good and the amp maker has the common sense to make the amp it sonic best, it really does not matter what they look like. If you want to see art, I will post pictures of my RK II V2 and my Matchless.
Either way, they both work. As far as wave soldering, as long as the boards are inspected you end up with a failure rate with parts per million, not the usual human error. Thank goodness we have it, or 95% of all consumer electronics would quadruple the labor cost and would be available only to the elite of society.

 

[Boogiebabies]

Gotta stick up for Bogner here,...

There construction technique and the quality of their parts is second to none. Ultra-low dissipation Wima metallized polyester and polypropelyne. Each type is chosen for a specific application. It's not haphazard. Silver mica caps.

In the newer amps, they've mounted their power tubes to the PCBs, but they've addressed the main concern (heat) by using power tube sockets with 1 1/2 inch legs so that there's enough room for air circulation. And the PCB itself is a work of art. VERY thick (3/24), re-inforced, through hole, well spaced out. Some of their amps use PCB mount pots (another 'no-no'), but they're the chunkiest pots I've ever seen: full-size, 24mm pots with huge brass shaft protectors.

What I love about Bogner is that they don't follow trends when it comes to how to build an amp. They think creatively about construction technique and component choice to deliver the absolute best, regardless of what the collective wisdom of 'experts' say.

That's topology and signal path design. Pot's have been mounted directly to the circuit board for over 20 years. It works, even if the "experts" disagree. Component selection is critical to an amps signature sound.
Sadly, everyone will eventually follow. The cost of doing business gets higher everyday. Looking at the labor intensity of Bad Cats, Matchless and other PTP makes, I do not see how they can stay afloat.

 

[Melodyman]

This is the Boogie Board. The Bogner board is over at HC.

If you read the post, it is basically ragging on all amps made with modern PCB's. When you get to stare down the guts of a Shiva, you may change your posistion. Rivera, THD, Diezel, Peavey, Carvin, Marshall, Fender and just about any other mass produced amp will have them. It's the design, integrity and quality of each integral component that make a goo PCB amp. The SLO 100 is well above industry standard and is used in my example. Granted, it's really just a two channel amp. As far as a transformer looking "Beefy", an amp designer can build or design a transformer for a specific impedence or a sonic variable. Just because it's "Beefy" does not make it better or worse. It is designed the way Rheinhold wanted it to. It has a specific load, winding, magnetisim and lamination thickness. Now a large transformer today fails in comparision to a 1951 Stromber Carlson PA with a lamination stack of 5 inches. One mans beef, is another mans jerky. O.K., back to PCB's. you cannot doubt that Randall Smith, Rheinhold Bogner, Peter Diezel and Horst Langer are not geniuses, but when you start seeing ribbon cables in amps, you have to wonder how far the progress is going to go. Fundamentally, if the design is good and the amp maker has the common sense to make the amp it sonic best, it really does not matter what they look like. If you want to see art, I will post pictures of my RK II V2 and my Matchless.
Either way, they both work. As far as wave soldering, as long as the boards are inspected you end up with a failure rate with parts per million, not the usual human error. Thank goodness we have it, or 95% of all consumer electronics would quadruple the labor cost and would be available only to the elite of society.

Thanks for the reply, I used to have a Shiva and I did take out the chassis once and the PCB looked decent

From the pics of Engl's that I've seen, they look like a level below Mesa and Bogner IMO, but I'm certainly no expert

 

[Boogiebabies]

Mesa has been using CC's in the Lone Star and RK II for the clean channels. It's awesome. It looks like a typical Mesa amp made in the same vain for about 20+ years. The contour section is nothing more than a graphic EQ with fixed inductor, capacitor and resistor values that basically give the amp the classis V shape, without the faders. The circuit boards in the current Mesa's all have the same look. They are mass produced in larger sheets and then snapped off.

BB, do you have any insight on how to mod this section? I'd LOVE to just swap a cap (If that's all that's involved) and tame the highs in contour mode a hair. Even better if I could put it to a push-pull pot. Sort of like the pull bright on the clean channel.

To change the frequency of the 6600 band of the Contour, you would need an inductance and capacitance calculation to change it. Since the inductor is fixed and would require removing the whole board to get at, changing the capacitance to your desired range is the best way to go.
The easiest way to make it switchable is to add a determined capacitance in parallel to raise or lower your frequency point. One side of the cap to the the input of the original and the other to the switch.

PM me with your amp and what frequency you would like to drop your 6600 countour to. I have the formula to get you either dead on, or very close.

 

[NuSkoolTone]

Mesa has been using CC's in the Lone Star and RK II for the clean channels. It's awesome. It looks like a typical Mesa amp made in the same vain for about 20+ years. The contour section is nothing more than a graphic EQ with fixed inductor, capacitor and resistor values that basically give the amp the classis V shape, without the faders. The circuit boards in the current Mesa's all have the same look. They are mass produced in larger sheets and then snapped off.

BB, do you have any insight on how to mod this section? I'd LOVE to just swap a cap (If that's all that's involved) and tame the highs in contour mode a hair. Even better if I could put it to a push-pull pot. Sort of like the pull bright on the clean channel.

To change the frequency of the 6600 band of the Contour, you would need an inductance and capacitance calculation to change it. Since the inductor is fixed and would require removing the whole board to get at, changing the capacitance to your desired range is the best way to go.
The easiest way to make it switchable is to add a determined capacitance in parallel to raise or lower your frequency point. One side of the cap to the the input of the original and the other to the switch.

PM me with your amp and what frequency you would like to drop your 6600 countour to. I have the formula to get you either dead on, or very close.

Hey thanks! Actually I'm OK with the Frequency(s) It's just the AMOUNT it's boosted. I'd like to take that slider down a notch or two. How many points is the Contour EQ made of anyway? 4? 5?

 

[Boogiebabies]

On a DC-2 it's 4, but I assume it's a 4 band in any typical Contour circuit.