WO 400 S2 R-Ch Distortion at Half Volume

[laatsch55]

If distortion was audible, run a sweep from 20hz to 20khz..

 

[Zstangl]

Just for reference guys, Zach has RevD PL400 backplanes installed and a RevG1 control board installed based on his order history. This may head off some additional questions you may be wondering about. I am assuming that Zach installed what he ordered.

Thank you for jumping in!! I most certainly installed everything you provided. I'll be sure to post this information in the future.

I appreciate the clarification on the bias test points. I assumed this to be the case but I've been burned by assumptions too many times to count.

I'm testing through a well worn pair of ESS AMT 1Bs. I need an excuse to replace the woofers and ribbons should something happen. I have an untouched 400 s1 that I'm using as a control.

If I find that the transformer is bad, what are my replacement options? Form factor is not a concern. I'd really like to go with a pair of toroidal units. What specifications would I look for beyond just In/Out voltage?

I want to replace my attenuator potentiometers. Can I go with something more common like a 10k?

I saw a video last year where they mentioned adding a small capacitor across the rectifier? It's been a while so I can't remember any details. They said it's standard on all their power supplies. Surely you're aware of this approach. I think I've seen or in your design but I would love some clarification. Sorry I don't have more information.

Thank you for your time!!

 

[Zstangl]

If distortion was audible, run a sweep from 20hz to 20khz..

Oh yeah, that makes sense. Why pick one frequency when I can have them all.

I was taking the scope for a test drive along with the amp a couple weeks ago. I had 8Ω resistors across the outputs along with the scope. At a very specific point the sine wave "grew spikes". I thought it was interesting but unimportant in the moment. Last night I was watching a video of a scope measuring a transformer that was overloaded (?) or otherwise failing and it showed the EXACT same signature.

If I do find that I've ruint this transformer, what are my replacement options? I am not concerned with form factor in the least. Do you know if there are toroidal transformers available that meet the specifications for this amp? If so, I'd probably go for a pair to get true separation.

I've read that the 700 has a higher rail voltage than the 400. If I am able to find replacements, can I increase the voltage for additional headroom? What are the trade-offs? What is the upper limit?

I appreciate your time and input. Really.

 

[George S.]

Since this is a Series 2, it should have a dual primary transformer. Are you sure you have it wired properly? The two solid color primary wires go to one leg of the power cord, and the two striped primary wires go to the other power cord leg(yes there is the main fuse holder in that circuit).
Bypassing the attenuators for fault finding was a excellent idea. Consider removing the DCP board temporarily and tacking the amps output wires to the speaker terminals for further testing. You have removed the Zobel Network from the DCP?
I really don't think your transformer is bad as you have a imbalance between the two channels. There is something different between the right and left channels/ sides of the amp. Most probably something very simple and therefore easily overlooked.
You are running the correct fuses for the fuse holders that are installed?

 

[J!m]

I like your piping right up until it enters the collector for the turbine. You have the blow-off valves there too but otherwise it looks like a decent flow path.

My other concern is the radiant heat from those pipes hugging the block. Oil temps from that, and (I assume) the turbo oil, will drive temps to the sky. The oil cooler will be larger than the intercooler…

Looks awesome!

 

[WOPL Sniffer]

Damn Sniff, did someone $hit in your raisin bran this morning.



The ability to solder and the need to test a transistor are not mutually exclusive. Hell, they're barely related. As I mentioned in my post, electronics as a hobby have always take a back seat to other interests. See below for an example of a hobby that I've focused on instead. I designed and built the entire thing by hand View attachment 64915



I want this project finished more than anyone here. The easy path would be to have someone else just tell me what's wrong. In case you missed it in the original post, I put this kit together to further my knowledge. Confronting and working through this problem will do more for my advancement than anything else.



You're a native English speaker and have never heard of a Tilde?????? It looks like this ~ and it means "approximately". Glad you had the opportunity to learn something from me, I just wish I could say the same.

It should measure ~+85VDC and ~-85VDC then......

 

[Gepetto]

Oh yeah, that makes sense. Why pick one frequency when I can have them all.

I was taking the scope for a test drive along with the amp a couple weeks ago. I had 8Ω resistors across the outputs along with the scope. At a very specific point the sine wave "grew spikes". I thought it was interesting but unimportant in the moment. Last night I was watching a video of a scope measuring a transformer that was overloaded (?) or otherwise failing and it showed the EXACT same signature.

If I do find that I've ruint this transformer, what are my replacement options? I am not concerned with form factor in the least. Do you know if there are toroidal transformers available that meet the specifications for this amp? If so, I'd probably go for a pair to get true separation.

I've read that the 700 has a higher rail voltage than the 400. If I am able to find replacements, can I increase the voltage for additional headroom? What are the trade-offs? What is the upper limit?

I appreciate your time and input. Really.

1KHz will show you everything you need to know...

 

[WOPL Sniffer]

It should measure ~+85VDC and ~-85VDC then......

Shit in MY raisin bran? No, one of the guys asked for pictures to better help you and you shut him down.

 

[Gepetto]

I asked for help in learning how to troubleshoot a problem. I'm not interested in being spoonfed the answers. You and I are not the same.

Hi Zach
What the guys are trying to tell you is that many debugs have occurred through the benefit of this forum and the folks here that are willing to help with problems. No one here can guess their way to your success.

EVERY SUCCESS was because pictures were shared which usually led to a finding and a subsequent solution. Like you shared a photo of your motor with us, the generous guys here need something to go on.

 

[MusicSteve]

Make sure your light bulb tester not hook up?
Check your output speaker Cap and resistor (Rt and Lt) are not hooked up? (new board has them on the WO Board I think?) what would that do Joe to have both hooked up in parallel?

 

[WOPL Sniffer]

I'm not interested in being spoonfed the answers. You and I are not the same.

The easy path would be to have someone else just tell me what's wrong


SpoonFed?? That don't SOUND like what your asking for.

Yer right, we're nothing alike

 

[Zstangl]

Hi Zach
What the guys are trying to tell you is that many debugs have occurred through the benefit of this forum and the folks here that are willing to help with problems. No one here can guess their way to your success.

EVERY SUCCESS was because pictures were shared which usually led to a finding and a subsequent solution. Like you shared a photo of your motor with us, the generous guys here need something to go on.

Hi Zach
What the guys are trying to tell you is that many debugs have occurred through the benefit of this forum and the folks here that are willing to help with problems. No one here can guess their way to your success.

EVERY SUCCESS was because pictures were shared which usually led to a finding and a subsequent solution. Like you shared a photo of your motor with us, the generous guys here need something to go on.

Joe,

I had a different vision in mind when I came here seeking assistance. I assumed the (mostly) wonderful group here would walk me through some test procedures using instrumentation and measurements. I hoped this process would further my understanding of the circuit operation and electronics design in general.

I shouldn't have made any assumptions as my experience level is barely above zero. I had no idea that a simple visual inspection would be so critical to the troubleshooting process. It makes sense though. I've coached many entry level technicians through the troubleshooting process in my industry. The VERY FIRST thing I tell them is to take it apart and see what looks out of place.

A visual inspection is almost certainly the most powerful troubleshooting tool in my box. Obviously, the same holds true for this hobby as well. As such, I found some time to take a few pictures. I'll present them in a separate post.

I appreciate your help so far.

 

[Zstangl]

I like your piping right up until it enters the collector for the turbine. You have the blow-off valves there too but otherwise it looks like a decent flow path.

My other concern is the radiant heat from those pipes hugging the block. Oil temps from that, and (I assume) the turbo oil, will drive temps to the sky. The oil cooler will be larger than the intercooler…

Looks awesome!

They will get coated with a true ceramic by SwainTech. If that's not enough, I'll wrap them as well.

 

[Zstangl]

Here are the pictures that have been requested. Sorry I didn't post them sooner, I had different expectations when I first posted.

 

[WOPL Sniffer]

First glance, thinking cold bad solder joints, possible solder balls. Ya gotta clean the hell outta them boards.

 

[WOPL Sniffer]

The Phoenix header connectors are on the wrong side of the board and may be causing an issue since there is no room on that side of the board for the connectors AND wires..

 

[Zstangl]

The easy path would be to have someone else just tell me what's wrong


SpoonFed?? That don't SOUND like what your asking for.

Yer right, we're nothing alike

I'm shocked that the admins on this site allow this type of behavior. I would expect this kind of thing on a site with a teenage demographic but not on a site composed of accomplished adults.

You lack tact and class. Your sophomoric, adolescent, and unprovoked criticisms do nothing to advance the discussion.

You bring the collective IQ and EQ down significantly. Your behavior reflects poorly on this entire group. It's unfortunate.

I've spent years eliminating this kind of behavior from my life. I have zero tolerance for this level of immaturity. I certain that you lack the minerals to speak like this when face to face.

I came here for help with a basic problem in a hobby that is STRICTLY for enjoyment and a way to unwind.

I expected an enjoyable exchange with fellow enthusiasts. Instead I've found my self irritated with your nonsense. You've sucked the fun out of this experience for no reason other than to stroke your fragile ego.

I appreciate the help and advice from the other members here but I'd rather figure this problem out on my own than suffer through any more of your vitriol.

I'm closing and deleting my account.

 

[WOPL Sniffer]

Dang, I was trying to help you. And I would have fixed your amp for free. Sorry. I already figured out what was wrong with it.

 

[WOPL Sniffer]

I'm shocked that the admins on this site allow this type of behavior. I would expect this kind of thing on a site with a teenage demographic but not on a site composed of accomplished adults.

You lack tact and class. Your sophomoric, adolescent, and unprovoked criticisms do nothing to advance the discussion.

You bring the collective IQ and EQ down significantly. Your behavior reflects poorly on this entire group. It's unfortunate.

I've spent years eliminating this kind of behavior from my life. I have zero tolerance for this level of immaturity. I certain that you lack the minerals to speak like this when face to face.

I came here for help with a basic problem in a hobby that is STRICTLY for enjoyment and a way to unwind.

I expected an enjoyable exchange with fellow enthusiasts. Instead I've found my self irritated with your nonsense. You've sucked the fun out of this experience for no reason other than to stroke your fragile ego.

I appreciate the help and advice from the other members here but I'd rather figure this problem out on my own than suffer through any more of your vitriol.

I'm closing and deleting my account.

I can't pronownce haff dem words......

 

[Gepetto]

Zach did you solder your output transistors into the backplane boards instead of using the sockets provided? It appears that way in the photos.