The Phoenix: Jer rebuilt WOPL 500

[Northwinds]

Amp arrived today. Yeah, the title of this thread is appropriate. I am nicknaming it the Phoenix because this was probably one of the worst train wrecks brought back to life, literally from the ashes as so much was blown up and missing. Jerry did a helluva job. You guys know the deal with this one though in the thread in Build a Monster

Ok, the system, nothing that compares to most of you guys but it serves my purposes well

WOPL400 (now 500 LOL)
Carver CT-24 preamp
dbx DX5 cd player
a/d/s C2/3 cassette deck
TT are a Diatone DP-86DA and a Pioneer PL-550, both running Shure carts
Cerwin Vega E-712 3-way 300w floor monitors


After carefully hooking everything up, powered up the beast. Love the blue lights and the Jerified faceplate (pics will be in soon)

Since the amp will not fit into my rack (just a bit too wide) I had to take the TT out and the WOPL resides on the top of the stand. Using interconnects and XP cables

Put in a ZZ Top cd and hit play. I chose My Head's in Missippi and set the volume at 9 o'clock with tone controls set to middle position. Sounds great so I applied the gas a bit about 11 o'clock and I immediately noticed at how fast this amp is with transients. The snares and everything hit violently, straight up startled me. Bass was tight yet defined... and POOF, tweeter proections activated. I freaked out but lowered the volume down to zero, waited a minute and turned it up again, tweeters reset all good. Backed the treble down into the negative range and applied the power. Just past noon, the main crossover protection was activated on both speakers. Waited a couple minutes for them to cool down, verified they were on and killed the tone controls on the preamp, killed the DAIR and Ambience controls on the DX5. Aplied the gas and got to about 1 o'clock on the preamp and

WOW, tunes just seemed to explode out of the speakers. You can't beat a well build SS amp for hitting hard

Time for me to experiment with this as I saw 120w peaks registered well before noon position on the preamp. The CV's should be able to take everything this has to offer but the transients I believe are what set off the protections

Going from dead slilence to the crack of a snare like that is like having the kit right in the house right in front of you. Working on dialing in the bass reponse more but in reality, direct signal flat sounds fabulous. I could not be more pleased. I think maybe a BBE will be in order for this also over an eq

I will get back to this thread with trying different media, I really want to see how the TT works with this but have to figure out how to make space for it and still keep it far enough from the amp

Jerry, don't know what to say except you rock as well as everyone else who offered advice in the build thread. I know you took a bath on this hooking me up in my current financial situation Jer, I plan on sending you more goodies to come

I would not hesitate again referring Jer's service for a rebuild and will extoll his name for years to come. Top notch work and abundent patience pays off in reviving something that was just a hunk of metal. Joe and White Oak deserve a lot of credit also for specializing in these beasts and not only making them better, but safer to use (I never told the wife that these amps were called "Flame" Linear's because she would be scared to death of it in the house. No worries on that account though and some things are best left unsaid when dealing with anxiety prone significant others LMAO

 

[Northwinds]

Noticing some things I would not normally worry about using a standard receiver/amplifier. The WOPL does not like you to mess with the tone controls. An example... at 9 o'clock on the preamp volume, if I boost the bass and the treble a bit (+1 position), the amp gets hot as hell and eventually a well timed bass note will trigger the internal crossover protectors in the CV's. Keep in mind this is at needle indicated 60w per channel when this happens

Awhile ago, I was playing a CD of Great White's Twice Shy album. Normally I set the controls to flat with regard to the tone but this album sounds good with a little bit more thump dialed in. Preamp volume at just a hair over 9 o'clock, bass set at +1 and treble staying flat (0). Was listening for a good ten minutes then I noticed the volume suddenly creeping up by itself. I ran over to the amp, lights on the meters went completely out, speakers tripped and I immediately shut everything down. The top plate of the WOPL 400 was hot enought to blister the skin if someone foolishly touched it for more then a few seconds

What could cause this? I have Monster gold plated heavy duty interconnects all in correct polarity and running Monster XP cables (same exact length and correct polarity of course) to the 8ohm Cerwin Vega E-712's and they are rated at 300w which should be more then sufficient to handle the amp's power

Anyway, after waiting a few minutes until I heard the internal speaker protections click back on, I went over and fired up the amp. Meter lights are on and everything seems to be running fine????

Your thoughts on this would be much appreciated. The amp running hot enough to fry a burger at low volume levels is a concern. Does the tone controls somehow create an issue the the WOPL does not like? I have not noticed the amp getting hot like that when I leave the tone controls alone

 

[Gepetto]

Noticing some things I would not normally worry about using a standard receiver/amplifier. The WOPL does not like you to mess with the tone controls. An example... at 9 o'clock on the preamp volume, if I boost the bass and the treble a bit (+1 position), the amp gets hot as hell and eventually a well timed bass note will trigger the internal crossover protectors in the CV's. Keep in mind this is at needle indicated 60w per channel when this happens

Awhile ago, I was playing a CD of Great White's Twice Shy album. Normally I set the controls to flat with regard to the tone but this album sounds good with a little bit more thump dialed in. Preamp volume at just a hair over 9 o'clock, bass set at +1 and treble staying flat (0). Was listening for a good ten minutes then I noticed the volume suddenly creeping up by itself. I ran over to the amp, lights on the meters went completely out, speakers tripped and I immediately shut everything down. The top plate of the WOPL 400 was hot enought to blister the skin if someone foolishly touched it for more then a few seconds

What could cause this? I have Monster gold plated heavy duty interconnects all in correct polarity and running Monster XP cables (same exact length and correct polarity of course) to the 8ohm Cerwin Vega E-712's and they are rated at 300w which should be more then sufficient to handle the amp's power

Anyway, after waiting a few minutes until I heard the internal speaker protections click back on, I went over and fired up the amp. Meter lights are on and everything seems to be running fine????

Your thoughts on this would be much appreciated. The amp running hot enough to fry a burger at low volume levels is a concern. Does the tone controls somehow create an issue the the WOPL does not like? I have not noticed the amp getting hot like that when I leave the tone controls alone

You probably tripped the thermal cutout in the amp which is why its lights went out.

You may have a lot of subsonic coming out of your preamp when you crank the preamp tone. You won't be able to hear it but the White Oak amp will amplify it almost down to DC. You said your speaker protection also cut out which is a good indication that this might be happening in your system. Do you have a different preamp?

 

[Northwinds]

Unfortunately no, I thought a Carver preamp running a Phase Linear would be pretty close to perfect since the same guy designed everything. Guess that's what I get for assuming LOL

The preamp also has driven a few other amps before this one and I did not notice any issues except when it was running a 600w DJ amp. That amp got wicked hot too but I was pushing it near full volume into a pair of Altec Voice of the Theaters for several hours

I suspected that the preamp was feeding too hot of a signal and the tone has something to do with it, just did not know how to explain it

 

[jbeckva]

Is there plenty of ventilation above and below it? How about the speakers? 1 pair only, and are they 4 or 8 ohms? If running 4's, Joe correct me if I am wrong but the recommendation is to have external airflow to the back.

 

[jbeckva]

Also might want to recheck the bias. If you have a voltmeter we can guide ya along... It may be running too high for ya.

 

[Gepetto]

Is there plenty of ventilation above and below it? How about the speakers? 1 pair only, and are they 4 or 8 ohms? If running 4's, Joe correct me if I am wrong but the recommendation is to have external airflow to the back.

Yes if you are cranking it...

 

[Northwinds]

Is there plenty of ventilation above and below it? How about the speakers? 1 pair only, and are they 4 or 8 ohms? If running 4's, Joe correct me if I am wrong but the recommendation is to have external airflow to the back.

One set of Vega's and they are 8ohm, the amp sits on the top of my audio rack (won't fit in it) with all the room it could want

I only pushed the amp to half volume once and it immediately tripped the speaker protections which I thought odd, I can max my neighbors big Crown 250w amp through the same speakers. Lately, no higher the a hair above 9 o'clock volume wise, any higher and the kids and wife quickly find a reason to leave the house LMAO

Ohm meter? No fripping way am I putting two metal rods in this thing LOL. I remember the high voltage crack and getting thrown into a wall accidently touching the wrong thing on a TV years ago, this would probably knock me through the chimney

 

[jbeckva]

Joe looks like the outputs from Ron's pre are cap coupled, but what about those muting transistors (Q4 and 5)... 945's (aren't those high on the suspect list?)

 

[Northwinds]

That was me just calling you Jer, you did not answer so I guess it's too late. Easier to talk but I am watching this thread like a hawk. I think the Carver is putting too hot of a signal into the amp. Seems wierd that I can't take this amp all the way to clipping with these speakers (if I wanted to)

 

[Northwinds]

Joe looks like the outputs from Ron's pre are cap coupled, but what about those muting transistors (Q4 and 5)... 945's (aren't those high on the suspect list?)

View attachment 10182

Time for a WOCT-24 eh?

 

[jbeckva]

That was me just calling you Jer, you did not answer so I guess it's too late. Easier to talk but I am watching this thread like a hawk. I think the Carver is putting too hot of a signal into the amp. Seems wierd that I can't take this amp all the way to clipping with these speakers (if I wanted to)

Well IF you did have a meter the first easy check (and it won't put ya through a wall or nothing)... with no signal in, measure the dc voltage if any across the speaker terminals. I'd be checking that first....

Did this just start today or no? Also you're spinning LP's right? Do you have a subsonic filter option on the pre you can turn on, then see? Like Joe is saying, the WOPL's can do it all the way down to DC pretty much, so any rumble on the TT is going to add to watts you don't see (or hear) but will definitely cause more current to the speaks than it should. Try a CD... or have you yet?

How are you measuring that 60W? Do you have an external wattmeter in line with the speakers or are you looking at the meters?

(lotsa good questions)... we'll figure it out.

 

[Northwinds]

Well IF you did have a meter the first easy check (and it won't put ya through a wall or nothing)... with no signal in, measure the dc voltage if any across the speaker terminals. I'd be checking that first....

Did this just start today or no? Also you're spinning LP's right? Do you have a subsonic filter option on the pre you can turn on, then see? Like Joe is saying, the WOPL's can do it all the way down to DC pretty much, so any rumble on the TT is going to add to watts you don't see (or hear) but will definitely cause more current to the speaks than it should. Try a CD... or have you yet?

How are you measuring that 60W? Do you have an external wattmeter in line with the speakers or are you looking at the meters?

(lotsa good questions)... we'll figure it out.

Pretty much an issue since I hooked it up, if I try to put the gas to it at all, either the tweeters trip or the whole crossover protection kicks in. If I back the tone controls all the way negative, I can maybe hit noon on the volume before the speakers trip

I do have a meter but I need to get a battery for it, I will tomorrow

Can't play lps, the amp occupies the spot where the TT used to sit. Just CD's and an occasional cassette

60w as indicated on the meters (pretty steady) but I do know the meters are not falling back to 0. They sit at about 20w or so so I just turn it up enough to get them moving, barely idling so in reality, probably 80w in reality

Other then this issue, at normal listening levels (like right now), it's fine

 

[jbeckva]

How about at idle?... let it sit for 10 mins with no signal, and then see how warm.

Then if it is warm or warm to hot, any difference on the left and right heatsinks?

 

[Northwinds]

It only gets hot when I jack up the tone controls from what I see though it's the top cover plate that is getting hot, I did not notice the heatsinks being unduely warm. It's been on for a half hour now at coversation level and does not feel hot like before

What setting do you want on the DC, I have a range of 10v-500v, rummaging for a battery now

 

[Northwinds]

Well, tried every setting on the DC voltage across the terminals and I get zip yet I can test the AA battery and it tests fine. I take it that a good thing that there is no DC voltage? Needle does not even try to move

 

[jbeckva]

It only gets hot when I jack up the tone controls from what I see though it's the top cover plate that is getting hot, I did not notice the heatsinks being unduely warm. It's been on for a half hour now at coversation level and does not feel hot like before

What setting do you want on the DC, I have a range of 10v-500v, rummaging for a battery now

What's your meter look like? Is it analog? The 10v range is fine, I'd gather..

 

[jbeckva]

Yeah actually.. post a pic of your meter first... better not assume anything and play it safe...

 

[Northwinds]

Analog... it's an A.W. Sperry SP-5A, no pic handy. I just tested a new AA battery and it tested perfectly at 1.5v in the mA setting just to make sure it worked correctly

Here is a image off the internet of the exact same one

 

[jbeckva]

Yeah give it a shot on the DC offset measurement. No signal... measure between the pos and neg posts for both left and right speaker outputs. You should NOT see hardly anything.. but report what you do see.

I dunno if it will do for the bias meas tho.. We want to be able to adjust that to around 360-380mV.. lil less than .4 volts...

That can wait.. this one here's the "big question" measurement... go for it.