WOPL 400 Build Problem!

[grapplesaw]

Latest update... I got the amp back. Before I went to hook it back up I ran some test on the pre-amp. I should have tested it before but I just wouldn't believe it could be it as I have been using it for about 2-3 years ever since I had had it restored by Carver Audio Repair.

I need to do some research but I have about 250-270mvdc on the left channel whereas the right channel is reads .0002mvdc

So apparently I did a good job building the amp..... WooHoo! Thanks everyone for your help...! Now I'll to start a thread on trying to fix the preamp... although I think it might be over my abilities! And/Or buy a different preamp, though I am partial to my Carver C4000!

There are several threads on these units. I have one and had problems. I found may of the boards can be removed and still have it work. You may want to remove the amp board for the delayed speaker section and see how that effects things. Being a amp section it maybe is back feeding into the low level sections.
Just a thought.

 

[Northwinds]

I ran into a similar problem last night with my Kenwood Basic C2 preamp... I hooked up a cassette deck and ran into Tape 1. When I turned the volume up to about 1/4 volume, my M-504 tripped. I tried again and it tripped. Started to freak out as I did not want to blow my only working amp but I ended up pulling the RCA's from Tape 1 and ran them into the CD input and no problems. What gives??? Is my preamp shooting DC into the amp when I am using the Tape 1 in???

I also notice for a second or two when I first power up the preamp I get a little distortion in the left speaker and in a second it's gone. Is it time to switch preamps before I potentially hurt my M-504? Anybody here recap the Kenny's? It seems to work fine when spinning CD's or the turntable

 

[nadude98]

I ran into a similar problem last night with my Kenwood Basic C2 preamp... I hooked up a cassette deck and ran into Tape 1. When I turned the volume up to about 1/4 volume, my M-504 tripped. I tried again and it tripped. Started to freak out as I did not want to blow my only working amp but I ended up pulling the RCA's from Tape 1 and ran them into the CD input and no problems. What gives??? Is my preamp shooting DC into the amp when I am using the Tape 1 in???

I also notice for a second or two when I first power up the preamp I get a little distortion in the left speaker and in a second it's gone. Is it time to switch preamps before I potentially hurt my M-504? Anybody here recap the Kenny's? It seems to work fine when spinning CD's or the turntable

Check with Echowars on AK, he does a lot of Kenwood... His home system is Kenwood.

 

[nadude98]

New question.. amp has been running great! Just noticed something the yesterday and it did it again tonight. About 3-5 seconds after I power it off I hear what I guess I would call a chirp. It's not real loud. I'm guess it's not normal, and I only noticed it yesterday and I will admit I had it cranked! A little My Morning Jacket on Austin City Limits.
Any ideas?

 

[laatsch55]

Running a DC protect?

 

[nadude98]

Running a DC protect?

Nope....

 

[Gepetto]

New question.. amp has been running great! Just noticed something the yesterday and it did it again tonight. About 3-5 seconds after I power it off I hear what I guess I would call a chirp. It's not real loud. I'm guess it's not normal, and I only noticed it yesterday and I will admit I had it cranked! A little My Morning Jacket on Austin City Limits.
Any ideas?

It is normal. The OPA134 stays in regulation down to when the rail voltages hit +2/-2V on the B+/B- rails. After that it is below the minimum voltage to maintain control of the output. That is the last gasp noise the amp produces when running on a total of 4V.

 

[nadude98]

It is normal. The OPA134 stays in regulation down to when the rail voltages hit +2/-2V on the B+/B- rails. After that it is below the minimum voltage to maintain control of the output. That is the last gasp noise the amp produces when running on a total of 4V.

awesome...! Thanks for the response.

 

[nadude98]

The WOPL is home and singing!

Thanks jbeckva!

 

[jbeckva]

The WOPL is home and singing!

Thanks jbeckva!

That's great to hear! How is it doing heat wise with the Maggies, etc?? How's the sound?

For info to all - I got this one a few months back, and it was a serious BATTLE.. The end result was an issue with the current limit circuit that was eventually bypassed due to James here having Maggies, and given the current required I did not feel comfortable leaving the circuit enabled. Overall James' build was decent and I really couldn't find anything off with it, but a few emails with Joe helped me get this sucker out the door (thanks Joe!)

But heck.. James got himself new 14 awg throughout, including the secondaries, plus a couple of new 12K caps in the process, so all of that in combination should make for one beefy bitch of a WOPL...

Here's it right before I sent er out...

 

[jbeckva]

^^^^^^ Minus DCP, which I added later LOL ^^^^^^

 

[nadude98]

It's sounds great! Maggies are singing... I will definitely need some cooling fans for sustained listening. Just playing 2 sides of Roger Waters "The Wall" got her heated up and sweaty. No more "blat" sound!

 

[roccus]

It is normal. The OPA134 stays in regulation down to when the rail voltages hit +2/-2V on the B+/B- rails. After that it is below the minimum voltage to maintain control of the output. That is the last gasp noise the amp produces when running on a total of 4V.

I get that quite a bit on mine to when I crank it I thought it was the speakers at first....