Since I learned that that one online dealer is authorized (not sure if I am supposed to say the name). I have stopped contemplating the other online dealer who is NOT authorized and have been browsing the authorized one even though they are a bit more expensive. I am willing to pay more for authorized.
Having said all that with the group buy going on I will go through that to buy anything at this time. But I just thought I would let you know that even cheap consumers like myself will take note of who is authorized and not even online.
Please don't listen to anything I just wrote, I am probably lying. If I am not lying then I am probably just plain wrong. Current Build Log and My New Rear End
Since I learned that that one online dealer is authorized (not sure if I am supposed to say the name). I have stopped contemplating the other online dealer who is NOT authorized and have been browsing the authorized one even though they are a bit more expensive. I am willing to pay more for authorized.
Having said all that with the group buy going on I will go through that to buy anything at this time. But I just thought I would let you know that even cheap consumers like myself will take note of who is authorized and not even online.
I'm not so sure buddy. I think you are smarter than most. Seems that warranties do not matter to so many people, and unfortunately, they are the people that need the warranties the most. I am willing to pay a little extra as well...
Jimmy has been removed for some quality vacation time with himself.
subscribed.
Edit-I am absolutely loving the source units.
Definitely making me reconsider buying the new Sony double din model (BT70 I think).
I have a question though.
When will we see a true indash double din unit that plays blu-ray?
I can't understand why I can buy a SONY home blu-ray player dirt cheap now but nothing for our vehicles.
Maybe I'm missing something but dvd is going the way of VHS.
Bret
PPI-ART COLLECTOR
EVERYTHING LOUDER THAN EVERYTHING ELSE-Meat Loaf
TEAM GRIZZ
Last edited by PPI-ART COLLECTOR; 03-27-2011 at 11:47 PM..
Reason: Didn't want to double post.
Subbed as well. I was thinking Stealths but The more I ponder it, the more the PPI Phantoms sound like what I really want. It seems the size of the two is really close.
Grizz keep doing what yo do, man. The "haters" are loud but they are also a minority.
They are also using their very own rope to hang themselves.
"...We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights...Whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or abolish it..."Whoever must have written that document must have been as "crazy" as those OPPT guys. /sarcasm --- OPPT-IN folks.
Subbed as well. I was thinking Stealths but The more I ponder it, the more the PPI Phantoms sound like what I really want. It seems the size of the two is really close.
Grizz keep doing what yo do, man. The "haters" are loud but they are also a minority.
They are also using their very own rope to hang themselves.
Thanx man. The Phantoms are a bit smaller but have alot more power since they are Class D and not AB like the Stealths...
Thanx man. The Phantoms are a bit smaller but have alot more power since they are Class D and not AB like the Stealths...
Sound quality comparable though?
Shoot, I really liked the DTR's (and obviously was head-over-heels in love with the HRU), and is the frequency response plot pretty flat? I know some previous full-range class D's I've owned did well in many areas but had some "brittle-ness" and a bit of grainy top end.
"...We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights...Whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or abolish it..."Whoever must have written that document must have been as "crazy" as those OPPT guys. /sarcasm --- OPPT-IN folks.
Not one product that will ever come out of Epsilon will ever compare to a Linear power or Blues product. You are on one level....and they are far above that. There is something called sound quality.....I am sure thats a new phrase to Epsilon. Might want to grab a dictionary.
Its not even worth discussing with you....your market is not the same.
I know you're taking a mini vacation now, but I have to say this one thing about your LP fetish: I recently measured a 100% functioning Linear power "IQ" series for crosstalk. 26dB. Yeah, that's quality.
Next, it had a 10dB channel imbalance at the lower 25% of the gain adjustment. It got to about 1dB at best. Still not awesome but semi-acceptable.
Sooo...no.
"I am one of the ones who contributes, dude....advice, tech support, design, and whatever. Especially the whatever." - cajunner
Some of the amps look nice, but most of their new speakers and subs remind me of flashy audiobahn flea market crap.
(Yes, this is based on looks)
Thank you! The only subs that I controlled the cosmetics on was the boring OS looking Art SQ series with virtually no custom tooled parts... I did the PC subs as well, but not the Candy red. It is a beautiful color, but I am getting my way and they will be more subdued with the black/copper that has been received so well. As for the regular Art subs, they perform very well, but I keep waiting for some sort of alien to crawl out of it. Looks like some weird sort of space ship... NOT MY IDEA!!!
I'm a big fan of the mini amps. A decade ago,i had huge Xtants, SSs, and PPIs in my trunk but now I ned all the space for diaper bags, red wagons, and the like. I like the simple look of the Phantom amps though would've preferred no giant round logo. The black ice look really nice but I can't fit those any longer.
Grizz - what is the switching frequency of the phantom amps?
I'm a big fan of the mini amps. A decade ago,i had huge Xtants, SSs, and PPIs in my trunk but now I ned all the space for diaper bags, red wagons, and the like. I like the simple look of the Phantom amps though would've preferred no giant round logo. The black ice look really nice but I can't fit those any longer.
Grizz - what is the switching frequency of the phantom amps?
Thanks.
Ummmm... Fast? lol I don't know, but I'll ask the amp engineer for ya...
I'm excited for these amps, I'm eager to see the production pics. The Litebox4 is the closest I can think of regarding power for the size, other than the usual suspects (Alpine PDX, Pioneer PRS, you know the drill)
"...We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights...Whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or abolish it..."Whoever must have written that document must have been as "crazy" as those OPPT guys. /sarcasm --- OPPT-IN folks.
You know me man. If I don't know something, I'll tell ya straight up! Just not my bag, but I am trying to get an answer...
I actually thought it was funny. It's rather strange that someone wants to know the switching frequency while it is extremely unlikely this person has any reason to need this info when there are so many other important points about the design.
I would have responded similarly - even if I did know.
"I am one of the ones who contributes, dude....advice, tech support, design, and whatever. Especially the whatever." - cajunner
I actually thought it was funny. It's rather strange that someone wants to know the switching frequency while it is extremely unlikely this person has any reason to need this info when there are so many other important points about the design.
I would have responded similarly - even if I did know.
School me so I understand... What would the difference between higher and slower switching speeds? Might be nice to know since I have never heard this before...
I'm an EE and am interested to know. Aside from that, a faster switching speed means harmonics and intermods are also further up in frequency making for filtering easier (so lower noise floor), along with other benefits like smaller caps needed.
I appreciate Grizz looking that up for me, even if my intelligence level may not be high enough to comprehend it.
"...We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights...Whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or abolish it..."Whoever must have written that document must have been as "crazy" as those OPPT guys. /sarcasm --- OPPT-IN folks.
Narrow form factor to differentiate from the Jello/Alpine/Kenwood squares, most flexible processing section of the bunch by far from what I can see, and solid power. Don't know about price, but I hope they're cheaper than the Jello HD's.
I hope they do really well for you, because they look like a very solid addition to the market.
I'm perfectly happy with my current amp situation, but two of those P900.4's, or a P900.4 for the midbasses and a P900.5 to drive the widebanders (bridged) and the sub might just be in my future...
School me so I understand... What would the difference between higher and slower switching speeds? Might be nice to know since I have never heard this before...
I'll cover this topic as briefly as I can (and I'm never brief). You can Google much of this and correct me appropriately as I am going from memory. If you don't know the terms, there are nearly infinite resources online...
I'll bold the words that you might want to research.
FETs are only so fast. The larger the FET - in terms of Drain-to-Source voltage, current rating or actual die size, the higher the gate capacitance. Large package devices also have inherently high lead inductance that causes problems with overshoot, ringing and EMI control.
This, there is a definite trade-off that every designer must make WRT package size (and dissipation) vs. switching speed vs. current handling.
*cracks knuckles*
Think of a FET's gate as a capacitor (it pretty much is) that allows current to flow through the device. You can charge and discharge a capacitor by applying a voltage and letting it discharge through a resistor. Now do this quickly - like a couple hundred times per second. The capacitor resists discharging fully because of a property called dielectric absorption. A temporary fix is to decrease the resistor's value, but eventually you will have such a low resistance that you won't be discharging the cap so much as shorting out your voltage source. So what do you do? You have to actively discharge the capacitor by alternately switching the capacitor to GND. Or, you can apply a negative bias voltage when you want to discharge even more quickly; Essentially "sucking" the electrons out of the capacitor. But we're getting ahead of ourselves...
So, FET gate drive circuits have to be able to inject/discharge this capacitive charge very quickly to ensure that the device turns on and off cleanly and with as little overshoot as possible. Overshoot can actually be described as an effect of cross-conduction or shoot-through and is a condition in which a particular pair of FETs across the power rails (high side+low side) are ON simultaneously. This is bad because it draws a ton of current and heats up the FETs while not actually doing any work. Cross-conduction can be caused by a number of things:
1. Insufficient gate drive causing the FET to operate in its linear region.
2. Poor PCB layout.
3. Little or no dead time (deliberate condition where neither FET is commanded to turn on).
4. Uncontrolled dv/dt components (instantaneous rate of voltage change over time).
All of these can be attributed to the nasty parasitics that literally leech efficiency and decrease reliability. PCB layout is often a key player in how badly these parasitics affect the end results. Other things you'll see are ferrite beads on the FET's leads in attempts to reduce overshoot by introducing a damped inductive component (filter) that rejects ambient noise.
Okay, so where does this put the issue of switching frequency? There are three main points to consider:
1. Intended bandwidth of the amplifier audio signal
2. Accepted distortion levels.
3. power efficiency
The rule of thumb is to set the switching frequency 10x the highest audio frequency you intend to amplify. (details are not discussed here).
Higher switching rates do mean smaller filter components, but they also present a larger risk of producing radiated energy from the speaker wires. Some designs are so bad that they radiate from every cable and hole in the chassis.
Distortion mechanisms include: output filter inductor saturation, poor power supply filtering, unsymmetrical triangle generator waveforms and a host of other nonlinearities.
So the breakdown:
Low switching frequencies 50-150kHz are reserved for low bandwidth or very high power amplifiers. Remember, large FETs and large banks of FETs are hard to switch quickly - and forcing them produces cross-conduction and lower efficiency.
Medium switching frequencies 200-650kHz are the most popular for mainstream high fidelity.
High frequencies 750kHz and up are mostly specialized or miniaturized amplifiers such as those in MP3 players and Cell Phones where the highest power is under 1W.
Hopefully this will give you a little insight into the reasons certain switching frequencies are chosen. And it might also make you think twice about how difficult it is to design a really good Class-D amplifier...
"I am one of the ones who contributes, dude....advice, tech support, design, and whatever. Especially the whatever." - cajunner
Re: New PPI amps (Phantom & Black Ice)
If you don't know the terms, there are nearly infinite resources online... 
Linear Mode
