Phase Linear 400 Amplifier Upgrade to WOPL

[NavLinear]

I guess it's about time to do this as I've been listening to the rebuilt 3300 Series II preamplifier and the almost unmodified 400. It's been fantastic listening to this and getting my audio ears back as for me it's been some time since I've had anything of quality to listen to. Most of my audio gear I bought as a teenager or very early 20's and this gear has been stored away for a decade or so. Ihave way more test gear than audio - go figure.

I've installed the White Oak power supply caps and today I installed the White Oak LED board - thanks Joe for the cool designs. Had the meters pegged for a song or two today. The system is in an awful configuration but it sounds great! All the gear is naked and next to a couple of fluorescent lights and other noise sourcesbut for now this works. I'm attempting to refine my audio ear for the before and after WO mod.

One issue that's confounded me is a ticking noise that occurs when I first power up the system and at first lasted a minute or so - but only when music was playing. Well this noise could be emminating from anywhere so I needed to remove components one at a time to figure out where the problem is. I removed the preamp and then the EQ and the ticking noise was still there so now we're down to the CD source or the amp. Of course when I opened up the CD source and hooked up an o'scope the ticking noise went away. To make a long story short the last several days I've heard the popping noice but after several seconds of music this noise disappeared and would not raise its ugly head the rest of the day even when I would recycle the power. FCUK! Of course everyone knows that FCUK is an acronym - French Connection United Kingdom (clothing company).

So now I have this annoying ticking noise going on but only for a few seconds and when it happens I look at the o'scope and shit - it goes away. Oh well - I'll get it nailed down eventually. No biggie yet. I've seen this noise on the o'scope channel that's hooked up to the amp but that's not saying anything as I haven’t been able to eliminate it at the source yet. FCUK!! (see above).

I opened up the Rotel CD and guess what - lot's of Black Gatecaps! I'll insert some photos for your viewing pleasure.

Oh yeah - I have a couple of photos that might give Lee a woody - see attached.

My ongoing saga will continue. Shit - only allowed five photos per post!

View attachment 6888

 

[NavLinear]

Here are several more photos of the CD source for those that are interested. I've been looking at some possible upgrades for this unit but I'll need to weigh the cost versus benefit.

 

[speakerman1]

Here are several more photos of the CD source for those that are interested. I've been looking at some possible upgrades for this unit but I'll need to weigh the cost versus benefit.

Yes those Black Gates are just hype. I think you should upgrade to some others and send the BGs. To me.

 

[laatsch55]

Sheesh!!!!! I just thought I had a cool faceplate holder!!! You Mr. Nav have the coolest faceplate holder on the planet!!! I want to hear that story!!

 

[laatsch55]

What series are the BG's??? Got a frequency response curve on the "before" ??

 

[NavLinear]

Yes those Black Gates are just hype. I think you should upgrade to some others and send the BGs. To me.

Yeah - I was thinking of replacing them with these shown in the photo. Only two cents each.

 

[NavLinear]

What series are the BG's??? Got a frequency response curve on the "before" ??

The Black Gates were stock for the Rotels. Back in the 90's the Brits didn't scrimp and these were considered entry level players but received very good reviews. Some reviewers felt the Rotel's had a better sound than those costing several times more.

 

[NavLinear]

Sheesh!!!!! I just thought I had a cool faceplate holder!!! You Mr. Nav have the coolest faceplate holder on the planet!!! I want to hear that story!!

You gave me the idea! Actually more than one - so maybe more will spill out.

No real story - just sat down at lunch and sketched out what I thought would work after taking a couple of measurements of the faceplate and the locations and spacing of the heat sinks to come up with this. Of course having CAD tools and a Fused Deposition Modeling (FDM) machine helps.

The build area of the FDM is 16 x 14 x 16 inches and the faceplate holder is almost 20 inches in length so we had a couple of choices. Option one was to build it in two parts and then glue them together and option two was to build it as shown in the photos - slanted upwards. The brown material is the support structure and the white is the build material. Pretty cool stuff.

 

[laatsch55]

What did skratch say, "with a little technology......." ?

So, you're happy with the 3300??

 

[NavLinear]

What did skratch say, "with a little technology......." ?

I agree with Skratch - Technology helps a lot.

So, you're happy with the 3300??

Yeah - I'm very pleased with the preamp! Thanks for all the help with that one.

I wanted to listen to any sonic change the preamp had in the signal path so I did a couple of simple listening tests. The first thing I did was to connect the CD analog output direct to the amplifier and give it a listen for a basline. Then I added the preamp in the circuit and there was very little sonic change except now I could control the volume. Lastly I added in the 901 EQ and of course there was a sonic difference as it amplifies the signal in the lower and higher frequency range.

Oh - I'm fairly sure the annoying popping is coming from my source as it popped for maybe a minute this morning and I could see it at the CD output. It'll be fun to run this one to ground if I only get a few seconds of popping - I will need to study the schematic and bring out some test points. Too much fun.

 

[Skratch]

Is FDM the same as stereo lithography ?

 

[speakerman1]

Does anyone have a good top layout. So I can have a decal made and I can paint it. It is in pretty sad shape. Did you change anything in the phono section? Mine was making noise. I think lee changed the opamp? No sure. It does sound sweet now. I like the phono set up now. I bought enough things to do a bank of resistors on all the phono amps I have. See what happens when I get them all together.

 

[laatsch55]

I have a pretty good top on the latest one I got. It'll never see the light of day anyway. I'll send it with the 700.

 

[laatsch55]

Yeah - I'm very pleased with the preamp! Thanks for all the help with that one.

I wanted to listen to any sonic change the preamp had in the signal path so I did a couple of simple listening tests. The first thing I did was to connect the CD analog output direct to the amplifier and give it a listen for a basline. Then I added the preamp in the circuit and there was very little sonic change except now I could control the volume. Lastly I added in the 901 EQ and of course there was a sonic difference as it amplifies the signal in the lower and higher frequency range.

Oh - I'm fairly sure the annoying popping is coming from my source as it popped for maybe a minute this morning and I could see it at the CD output. It'll be fun to run this one to ground if I only get a few seconds of popping - I will need to study the schematic and bring out some test points. Too much fun.

I think they are pretty neutral also.

 

[NavLinear]

Is FDM the same as stereo lithography ?

Yep - same process different name. The files we use are .stl (stereo lithography). Different methods seem to get different names.

 

[Skratch]

Yep - same process different name. The files we use are .stl (stereo lithography). Different methods seem to get different names.

We have one at work, to make prototypes. Pretty neat stuff

 

[NavLinear]

I know it's been a while since I last posted in this rebuild thread but I'm not sitting on my laurels - just hunting down necessary stuff. I've come up with some MIL-W-22759 wire (different slash numbers as I am scrounging) in 20 and 18 AWG. I now have all ten of the solid colors as I'll be changing out the wires when replacing the controler board. The color coding of wires in my amp is slightly different than what is listed in Joe's spread sheet - see attached photo. The factory probably ran out of one of the colors that day. I'm plannig to use the 20 AWG wire as the interconnect between the board and external circuitry. The 20 gauge wire is overkill for the circuit but when the board is removed from the standoffs the wires are flexed so........

Another to do on my list. Must find 22 AWG wire in the same ten colors. I do have them in 26 AWG though.

One of this weeks goals is to fabricate a strain releif/transistor leg protector for the bias transistor. I want to use the same fastener mechanisim to make it a simple upgrade and not lose any of the heat dissipation characteristics with the existing mounting method. I have a mental picture of this but I need to put it on paper. I'll post the results next week.

I've included a photo of Joe's nice WO LED board as I wanted to show a small addition of nylon washers at the board mounting points. I really like the diffused blue LEDs.

 

[laatsch55]

So, got a sonic signature firmly embedded so you can note the difference after the WO board?? And where's all those test charts??

 

[NavLinear]

So, got a sonic signature firmly embedded so you can note the difference after the WO board?? And where's all those test charts??

Well - not exactly. I've been dicking around with the 8903 and it's time to get the baseline data for this guy. Kinda fun playing with it - the 8903 that is!

So far all the data I've taken has been by hand so I'll see what I can do to pretty it up. At this juncture I like doing the math till it's ingrained in the brain - I'll try not to kill those cells.

Off to the horses - must tend to their wounds as the flies have been terrible this year. One of our guys had the corner of his mouth chewed into (by flies) and the damned things layed eggs in the wound. Talk about disgusting. The vet had to cut them out and the wound smelled like rotton meat for the first two or three week. Oh well - the fun of it all.

 

[laatsch55]

Know all about it, old farm kid here. Pulling calves out of heifers bred to young, 20 below, middle of the night, and no one happy about what is going on, cow, calf or calf puller.