Jad Freer Sisma Mega Thread.

[Franz975]

@Andrea Lo I was just thinking about what AgedHorse was explaining at first about tube amp and wonder if the Sisma can push more than 700W (4ohms) if the Tube Preamp goes to overdrive ?

Also, I heard that the Wattage can be really different depending on which frequencies you based the power on, is that true ? And if so, what are the frequencies that a designer look at that need the power when making an amp ?

 

[DJ Bebop]

If it was me that you were asking I could go to any of my gigs and grab any of the heads I mentioned and I would have the same smile on my face. I don't chose one over the other for any reason. I'm pretty good at getting the sound I desire out of both Mesa heads and Sisma. I play an incredibly wide variety of music with multiple groups. I'm working in over 10 different kinds of musical adventures. They all work great. The DI's in both companies amps are great. I've received many compliments from musicians, sound techs and audience that my sound is right no matter what I use. You must find what works for you. Unfortunately one is not always able to try before purchase. I purchased all 3 amps without trying first. They both offer return if not satisfied so that was good enough for me. Actually better because I was able to use them in my real life situations instead of trying at a music store. Nothing was returned so I made good choices for myself. Sometimes ya gotta just jump in the pool.

Do you find the Sisma close to the sound and feel of the WD?

 

[Danny C]

Prior to getting the Sisma I was only using the two Mesa heads I mentioned since they both became available. I also have Markbass, PJB, Ampeg Fender and others but they stay home. Used, but at home. I became very happy when Mesa launched the Subway Series. I had no reason to look further. I got the Sisma out of curiosity and I dig that too. But that doesn't mean it's better than the Mesa heads, just different. I will continually use all 3 because they are all that good for me and my tastes.

 

[gtirard]

Yes it is, not as light as class D heads but close. Surely lighter and much more compact than an Aguilar DB751, that I feel more close as a comparison.

It would sure be very interesting to read a comparison between Sisma and the DB751, maybe one day…

@Danny C - I understand you don't feel like writting a full comparative review between Sisma and the Mesa 800+ and WD800… But like Franz975 suggested, maybe you can tell us in which context you would choose one or the other? Let's say you're packing for a gig tomorrow, you can only bring one amp, how do you choose?

 

[Danny C]

It's very hard to explain for me. I'm not good with tech terms nor do I profess to know that much about it. I love them both and whether the sound is the same or not, I don't know. They both have excellent DI's which I need. They both can make numerous tones that are usable, for me. I say for me lots because we all have different opinions of course. I bought them all cuz I can and use them all because I want to. I'm very sorry that I can't give you the answer as you have asked me this prior either here or another thread. I'm not smart enough to guide anyone properly. I love them both though.

 

[DJ Bebop]

It's very hard to explain for me. I'm not good with tech terms nor do I profess to know that much about it. I love them both and whether the sound is the same or not, I don't know. They both have excellent DI's which I need. They both can make numerous tones that are usable, for me. I say for me lots because we all have different opinions of course. I bought them all cuz I can and use them all because I want to. I'm very sorry that I can't give you the answer as you have asked me this prior either here or another thread. I'm not smart enough to guide anyone properly. I love them both though.

What part of the planet do you live on?

 

[Andrea Lo]

@Andrea Lo I was just thinking about what AgedHorse was explaining at first about tube amp and wonder if the Sisma can push more than 700W (4ohms) if the Tube Preamp goes to overdrive ?

Also, I heard that the Wattage can be really different depending on which frequencies you based the power on, is that true ? And if so, what are the frequencies that a designer look at that need the power when making an amp ?

1) yes, around 900W
2) our power amp has the same power an all the spectrum

 

[gtirard]

It's very hard to explain for me. I'm not good with tech terms nor do I profess to know that much about it. I love them both and whether the sound is the same or not, I don't know. They both have excellent DI's which I need. They both can make numerous tones that are usable, for me. I say for me lots because we all have different opinions of course. I bought them all cuz I can and use them all because I want to. I'm very sorry that I can't give you the answer as you have asked me this prior either here or another thread. I'm not smart enough to guide anyone properly. I love them both though.

OK don't worry… we tried Thanks anyway.

I'm willing to do the same exercice on my side, "when would I choose Sisma over my other amps for a gig?" - I've got 3:

• Quilter BB800 (I had it before Sisma)
• Sisma
• A brand new 50W tube amp that weight only 4.2 Kg

The problem is that I'm biased right now, because I'm still in my honeymoon with the new tube amp. I should wait until the honeymoon is over, and also should ask a friend to blind test me between Sisma and the tube amp to see how much of my opinion is based on the romantic idea of the power tubes.

 

[gtirard]

@Andrea Lo...wonder if the Sisma can push more than 700W (4ohms) if the Tube Preamp goes to overdrive ?

You shouldn't worry about it, I can't think of any situation where 700W wouldn't be enough, and even if it was, you'd probably use a 2 ohm cab setting in that case - and the Sisma is rated at 950w at 2ohm.

 

[Franz975]

You shouldn't worry about it, I can't think of any situation where 700W wouldn't be enough, and even if it was, you'd probably use a 2 ohm cab setting in that case - and the Sisma is rated at 950w at 2ohm.

Yep 700W is enough for me, the PA help if not. Last show I did the sound guy do a great job. Bassists of the others bands wanted me to explain how to get that lol. (guitarist who play bass don't make great bass tone I think XD)

 

[Franz975]

1) yes, around 900W
2) our power amp has the same power an all the spectrum

Nice to know

About the 2), if the bass and high are at the same power does that make this amp kinda agressive in the 2-4kHz range ? Because human audition is more sensible at those frequencies. Or it is "the same power" on all the Spectrum in the way it sound pretty flat for a human and so the bass frequencies would be more powerful to be as loud as higher frequencies ?


Also, how does guitarist (or bassist) don't break often a speaker if an amp can be more powerful that what is on the paper and so be more than what the cab can handle on the paper ?

 

[Andrea Lo]

Yep 700W is enough for me, the PA help if not.

Trust me, half would be enough.

 

[agedhorse]

I hope that all the feedback coming from real users will also prove the myth that whatever is not classD is primitive-livinginthepast-notwantingtoembracethefuture.

It's a different technology that may suite some players needs.

Perhaps you don’t remember that exactly the same arguments were made against Switchmode power supplies being inferior to traditional line frequency (linear) supplies. Fortunately that myth is dying faster than the class D myth and the Neo myth.

No, I would not!

I think he was quoting Danny C in his question.

Andy is more entitled to teach this but it’s not the power amp type that adds weight. It’s the power supply and the cooling system. Since almost all class D use a switching power supply they are lighter and being more efficent they don t need massive dissipators.

Correct, there are three reasons for the decrease in weight of an amp.

1. reduced power dissipation as heat… class D is the most efficient, followed by class G/H, then class AB. Higher efficiency reduces the size/weight of heat sinks (radiators) as well as the demand placed on the power supply.

2. Power supply topology…. A Switchmode power supply operates at higher than line (mains) frequency with a higher voltage DC (bulk bus), so the magnetics can be smaller and are easier to design for better performance (regulation) than traditional supplies. It’s also common to add power factor correction to further improve the inherent advantages.

3. Sheet metal chassis… when the internal weight is reduced, and the size is reduced, this opens up the options of lighter weight chassis design including the use of aluminum.

Prior to getting the Sisma I was only using the two Mesa heads I mentioned since they both became available. I also have Markbass, PJB, Ampeg Fender and others but they stay home. Used, but at home. I became very happy when Mesa launched the Subway Series. I had no reason to look further. I got the Sisma out of curiosity and I dig that too. But that doesn't mean it's better than the Mesa heads, just different. I will continually use all 3 because they are all that good for me and my tastes.

Exactly, we all have different personal tastes and in the end the player needs to choose an amp (or amps) that suit their own preferences and needs.

 

[Franz975]

Trust me, half would be enough.

I don't know that band but I know that I miss a great one with a bassist that use a Jad Freer amp and they were in my city Lol. I don't even know that place :O

 

[Andrea Lo]

Perhaps you don’t remember that exactly the same arguments were made against Switchmode power supplies being inferior to traditional line frequency (linear) supplies. Fortunately that myth is dying faster than the class D myth and the Neo myth.



I think he was quoting Danny C in his question.


Correct, there are three reasons for the decrease in weight of an amp.

1. reduced power dissipation as heat… class D is the most efficient, followed by class G/H, then class AB. Higher efficiency reduces the size/weight of heat sinks (radiators) as well as the demand placed on the power supply.

2. Power supply topology…. A Switchmode power supply operates at higher than line (mains) frequency with a higher voltage DC (bulk bus), so the magnetics can be smaller and are easier to design for better performance (regulation) than traditional supplies. It’s also common to add power factor correction to further improve the inherent advantages.

3. Sheet metal chassis… when the internal weight is reduced, and the size is reduced, this opens up the options of lighter weight chassis design including the use of aluminum.



Exactly, we all have different personal tastes and in the end the player needs to choose an amp (or amps) that suit their own preferences and needs.

I think the earlier example of switching power supply I own is my early 80's Walter Woods MI100-8. I also had one of the very first Markbass neo cabs, when it was the new thing in the early 00 and they were not yellow yet. Class D too, had a few, still own a couple. I'm not a tech myself so I just go with taste (and personal road statistics).

 

[Laurent]

It is interesting to witness that Italy as a relatively small country has had a fair amount of bass equipment innovation. I am thinking of Markbass which used neodymium speakers and class D amps early in the game. They of course did not invent these technologies but certainly popularized them. It now appears that Jad Freer is also pushing forward with a mix of newer technologies and time tested ones such as the preamp tube and Baxandall eq.

 

[gtirard]

It is interesting to witness that Italy as a relatively small country has had a fair amount of bass equipment innovation. I am thinking of Markbass which used neodymium speakers and class D amps early in the game. They of course did not invent these technologies but certainly popularized them. It now appears that Jad Freer also pushing forward with a mix of newer technologies and time tested ones such as the preamp tube and Baxandall eq.

Yes, and don't forget GR Bass with their carbon fiber ultra lightweight cabs (and Jensen/Sica and probably many others). Impressive.

 

[DJ Bebop]

Trust me, half would be enough.

Turn it down!
Turn it down!
I have children sleeping here
Don't you boys know any nice songs?

 

[Laurent]

Yes, and don't forget GR Bass with their carbon fiber ultra lightweight cabs (and Jensen/Sica and probably many others). Impressive.

Do not know that one but I am more interested in music than gear these days!

 

[Danny C]

DJ Bebop, US, east coast