700B WOPL Audition List

Northwinds · Mar 25, 2014

This statement bothers me from AK Lee, how much truth is there to this and how does it apply to our WOPL's? I thought they were super low distortion. They have to be low distortion or your K-horns would not be able to take so much power right?

What is the actual THD and S/N ratios on the new FC builds on average?

"Funny thing about this Nikko is that output transformers would not even be required with this configuration (* this unit seems to have a symmetrical power supply with positive and negative voltages). Must have been sound-wise considerations. Technically, output transformers are some of the worst things you could do; any device without them will perform better, no matter how well the wires are wound around the iron core in the transformer. It's a fact. Any device with an output transformer has a really high THD. The only reason why people still put those in is the tube-like distortions they produce (and THEY are the main reason for this "tube-sound", not the tubes themselves)."

I noticed on the data sheets that I posted for that guy from Stephen's a lot of difference between channels (the THD figures which is why I did not post those sheets). Not sure if before you shipped that you got the THD closer between channels or figured out why there was a difference that wide). That RCA410s were used and yet we no longer use them right, everything is MJ PNP/NPN's right? Perhaps I jumped the shark posting some of those data sheets since some components are not used now and improvments are constantly evolving? I have a lot of questions so I know what I am talking about. No one has said anything in reference to the sheets, the above quote is from another thread but maybe you can see my confusion

I am wondering if a lot of the comments I am seeing in some threads are from people who are really don't know shit about electronics

* Does the WOPL have a symmetrical power supply with + and - voltages? Is this what your talking about when discussing + and - rail voltages? What is the difference between symetrical and quasi and full comp? Is he talking about output transformer or output driver?

Thanks for your help in deciphering this stuff for me, what I would really like is a recent build test results with the latest stuff White Oak offers and what components used and why. I think Sally is the most recent build but I don't think Jer can print sheets like you do??? If I can wrap my head around this stuff a bit more, I would be much more comfortable passing info onto others who may have an interest in our WOPL's. I want to do this right and not make an ass of myself LOL

Maybe Joe or Jer can hop in and help me out if Lee is working today

I constantly see references to lower powered amps being "giant killers" and I just don't see how that is possible since it takes lots of clean power to avoid distortion (the old scissors "snip" deal). Amps of 125w or less just don't seem to have the reserve headroom to avoid distortion at high listening volumes

I love the WOPL's but a cheerleader should "know the moves" LOL and I don't want to break my neck doing a cartwheel LMAO

Northwinds · Mar 25, 2014

This is also another interesting thread about ratings. The WOPL's are tested across the frequency range and not with just a single frequency right. It was interesting to see that a McIntosh could not deliver it's published specs but was shutting down thermally and resetting. I know we can drive our WOPL's to insane levels without that issue (unless we really go overboard)

What is "weighted" testing?

I would love to be able to discuss this stuff in dumbass terms so that the average person (like me) can understand them and yet provide the right info so that those that know their shit will not snicker at the cheerleader with the big boobs but nothing between the ears LMAO

http://www.audiokarma.org/forums/showthread.php?t=21415

Lee responded in this thread

laatsch55 said:

I am confused since we call these WOPL1000's but what I am reading is 450 watts per channel which according to my math is 900w. What gives? See why I am confused. He also says he tested at one frequency (1kHz)? What would it test by the old way across the frequency range 20-20000?

Skynyrd77 · Mar 25, 2014

No lee no preamp yet! I'm assuming it's coming by USPS or it would of been here by now!! Ron that was a shitload of typing but some damn good questions! It would be great to know the ins and outs of the WOPLs .but like you said its hard to be a cheerleader when your in gym class with no clue!! There's got to be good dumb to oh ic kinda terms lol. But prob not! Maybe we need to go back to school Ron lmfao!!! I put up a WTB thread for a 700b on ak! See if that drums up anything! After having all that extra headroom I'll be on the lookout for 1 fore sure!!

Northwinds · Mar 25, 2014

Skynyrd77 said:

I saw the thread Jason and added to it LOL

I know I have not yet been able to max output Sally so I am sure you have not yet with Bertha. The 400s have gobs of headroom. The difference between a 700 and a 400 in only a few decibels

Ask Lee about that dude with the Aerosmith backline, perhaps he would be willing to sell you one (or two *hint*) 700B's since the deal fell through to purchase everything. If you could get a couple non-working one for around $200-300 each that would be the cat's meow

I have so much to learn about this stuff. One thing I don't want to do is overstate these amps. I know they are awesome, you know they are awesome and other Brother's on here know they are awesome but only a few people understand WHY they are awesome. I believe these amps will stand on their own merits without having to inflate specs. McIntosh made that mistake and their credibility has taken a hit. I don't want to see that happen with the WOPL's, especially since they are a newcomer taking on established heavyhitters. This is why I want to be educated so I do not make that mistake inadvertently

laatsch55 · Mar 25, 2014

Did you take the test results from the page I linked? There were some before testing that was terrible. I have to work this morning but will address this when I get back. Yes I test over the entire frequency. At 20hz, 200hz, 1000hz, 20,000hz. The smallest reading is wht the power ratings are announced. If necessary I'll print out all three . The frequency response should shed a light on the bandwidth power also. If there is 0db or close to it between 10-20K the power will be the same at all frequencies. There are no power output transformers, it's a direct coupled classA/B complementary output stage. If its whoaru99 he's just being a prick.

laatsch55 · Mar 25, 2014

In this particular amp 450 was all it was before reaching 1% distortion.

I've had some as high as 525 till I hit 1% distortion.

laatsch55 · Mar 25, 2014

A frequency response test is the result of pinging the amp with the same input level at 150 frequencies and measuring the output of the amp at that frequency. When we say it is essentially "flat" from 20-20,000 the power output will be the same over that bandwidth=power bandwidth. If he looked at the FR curves he would have known this. That's why the first test I run is the FR, theres a lot that can be inferred from that one test.

laatsch55 · Mar 25, 2014

The guy with the 700's was member---Phase Boston, got his phone number too if he doesn't answer a PM.

Northwinds · Mar 25, 2014

laatsch55 said:

Yes I did Lee (the page you linked), thanks for doing this. This is why I wanted updated testing results for the massses. Perhaps I should kill those sheets in the thread for now until you canget new updated ones up? No, not that prick, this was just someone commenting in a totally different thread and I figured I'd better ask. Wish you were closer Lee, you could setup a school desk and I would be your most diligent student

EDIT: I went ahead and removed the sheets from the post until we can get new ones. Better safe then sorry LOL

laatsch55 · Mar 25, 2014

S/N ratio was 104db unweighted and 114db "A" weighted Iec "A" weighted is an international standard filter inserted that limits certain frequencies and harmonics. Unweighted contains all frequencies and harmonics between 10 and 80,000 hz.

Northwinds · Mar 25, 2014

laatsch55 said:

That makes sense, you want to eliminate the frequencies that humans can't hear right?

laatsch55 · Mar 25, 2014

I'll post the entire A weighting conditions when I get back. There are a number of "weighted" tests which all require a filter of a specific design to conform to the test. Weighted figures always "look" better, which is why I always include the unweighted figures, that is the worst case scenarios, and if they who are challenging these figures read the tests correctly the AP prints the CONDITIONS of the test also...

laatsch55 · Mar 25, 2014

Northwinds said:

In some cases yes, in others an unweighted spec tells you a lot about open lop gain and rolloff...

laatsch55 · Mar 25, 2014

In these amps the left channel sems to test worse than the right, due to transformer interference and the left channel being closer to that interference..

laatsch55 · Mar 25, 2014

When you post the THD & N figures you have to post both the graph AND THE table. I inflate the gtaph to more clearly delineate the distortion difference at each frequency so it's easier to decipher. I can change the look of the graph by changing the vertical limits of the distortion percentage. The graphs are also logrithmic and can look really bad if you are not familiar with a logrithmic graph. The table is a strictly numerical accounting with no limits imposed on the pictorial representation to the limits or the other frequencies.

Northwinds · Mar 25, 2014

I think we need to work on a .pdf document that shows all the specs and also images of Joe's boards and explain how everything works. Going to have to be done eventually, especially if a line of WO amps is hitting the market in the future. A real professional document that explains things clearly to the average Joe but will also satisfy the requirements of techies

I am going to start looking into this but any help from Brothers that actually know how to do this would be awesome. I don't think this can be done right with a spreadsheet program, downloadable .pdf is the way to go

I am also thinking of building a sister website dedicated to WOPL info, all incarnations with links to this board and White Oak Audio (with all of your permissions of course and you would have total access to change/modify anything on a as needed basis. Yes, all the info is here but it's spread around so much that it would take forever for the average person to find the specifics and since things can change quickly, it might be a good vehicle or prototype for the upcoming WO line??? Joe could actually blog all this but I am sure he is too busy. Let's make these the next "fire discovery"

Just tossing ideas around, we have to get this stuff out to the world if "we" are to succeed. I can't wait until they start showing up at audiophile shows where people can actually hear and see them. I also would like a little more info about the one that is supposed to be done up for Bob Carver himself??? I think I remember a reference to this somewhere on here

If I am getting too far ahead of myself here, please slam on the brakes, I can get overly enthusiastic sometimes but man, you guys have me so commited to this amp and with everything you all have done for me, it's time for me to "earn my keep" but I want to do it the right way and in the best interests of the "brand"

ie pom poms with substance

Northwinds · Mar 25, 2014

laatsch55 said:

How can this be addressed? I assume a new chassis is where this really comes into play. You would want to center the tranny then instead of the current offset position?

laatsch55 · Mar 25, 2014

Steady and accurate is the way. What a lot of people don't understand is that topology has a lot to do with distortion and how it sounds. The Spec 2 has a magnitude better distortion specs than the wopl's, due to it's use of global negative feedback and very little use of localk feedback. The wopl's use lots of local negative feed back and very little glkobal feedback, the result the wopls "sound" better but don't "test" better. I have two excellent Spec 2's and they haven't been turned on in 2 years now...

laatsch55 · Mar 25, 2014

Outboard power supplies, Ron there is a trade off for super low distortion, the sterile sound....

Northwinds · Mar 25, 2014

laatsch55 said:

So bottomline in this case is hearing is believing. These need to make the the rounds of the show circuit defintely

I am going to spend a little time online researching and trying to make heads and tails of what you spoke about Global Negative Feedback and Local Negative Feedback. These are things I need to understand. Maybe it's time I look into an electronics course at UCONN :-o

700B WOPL Audition List

Veteran and General Yakker

Veteran and General Yakker

Veteran and General Yakker

Veteran and General Yakker

Administrator,

Administrator,

Administrator,

Administrator,

Veteran and General Yakker

Administrator,

Veteran and General Yakker

Administrator,

Administrator,

Administrator,

Administrator,

Veteran and General Yakker

Veteran and General Yakker

Administrator,

Administrator,

Veteran and General Yakker