JBL Performance Series

[jener8tionx]

Are you sure the brown stuff isn't some type of glue to give the caps some support other then the terminals? This is a pretty common practice.

Usually there is signs of pressure in the can like bulging. Or the just short and burst. But by reading your post it doesn't seem the be a power supply filter issue. Its something in the amp circuit or driver. Do you have a schematic?

It could be glue, but it looks like it is coming from below the pins in the capacitor (especially the top right one). If the cap was bad it could send a DC ripple into the circuit causing all kinds of problems not limited to the power supply area of the board. When I test the caps with a DMM I got a short in the cap on the top right. The others tested at 3M ohms, 3M ohms, and 5M ohms.

Here is the service manual link which includes a schematic:

http://www.jbl.com/resources/Brands/...400 Sub SM.pdf

[jener8tionx]

Update: Still stumped.

I put in the new capacitors and this time Q17 blew up and then before I could even flip the switch, the fuse blew. See picture below with the offending transistor circled and you can see the new caps as well.

I took all of the power transistors out and fired it back up (with yet another fuse -- I'm getting low!). No pops or blown fuses. I was able to get my DMM in there to measure some voltages.

V+ 50V
V- -49.9V
+15v cycling between ~13v and ~16v
-15v -10v

No clue what the problem is. Maybe to voltages are off because I have the power transistors out and they aren't drawing power, but I suspect that some component is either open or shorted and/or a voltage regulator is bad. I guess I will take a break for a bit and then come back and do a ton of voltage measurements and try to figure out what the problem is.

[Don C]

Once you've looked at all of the electrolytic caps, those tantalum caps would be my next suspects. The orange and blue dipped ones right in front. C104 and C109, can't see the designation on the blue one, but in my limited experience it's worth checking them. Edited to show which ones I mean.

[rpatt]

Update: Still stumped.

I put in the new capacitors and this time Q17 blew up and then before I could even flip the switch, the fuse blew. See picture below with the offending transistor circled and you can see the new caps as well.

I took all of the power transistors out and fired it back up (with yet another fuse -- I'm getting low!). No pops or blown fuses. I was able to get my DMM in there to measure some voltages.

V+ 50V
V- -49.9V
+15v cycling between ~13v and ~16v
-15v -10v

No clue what the problem is. Maybe to voltages are off because I have the power transistors out and they aren't drawing power, but I suspect that some component is either open or shorted and/or a voltage regulator is bad. I guess I will take a break for a bit and then come back and do a ton of voltage measurements and try to figure out what the problem is.

Did you make any progress?

[gferrell]

Usually if you have one shorted transistor and fuses are still blowing one of the other ones is shorted. Do you have schematics?

[rpatt]

Usually if you have one shorted transistor and fuses are still blowing one of the other ones is shorted. Do you have schematics?

See link in post #1996.

[JBLAddict]

Hi All,

just added an HTPS400 to my PS series HT, to complete the set.

I'm going from an L8400 with the Normal/LFE setting, where I used LFE for DD, DTS, SACD, DVDA

The HTPS has the Normal/THX setting and recommends for DTS and DD to use the Normal setting, using the xover and gain controls on the unit? However the THX setting which bypasses the xover and uses the preamp xover/gain seems a better match to my former LFE setting (except the gain which is still controlled in part on the L8400)

I don't have a THX pre-amp, can someone tell me what settings to use for my range of DD, DTS, SACD, DVDA material?

Thanks much

[rpatt]

Hi All,

just added an HTPS400 to my PS series HT, to complete the set.

I'm going from an L8400 with the Normal/LFE setting, where I used LFE for DD, DTS, SACD, DVDA

The HTPS has the Normal/THX setting and recommends for DTS and DD to use the Normal setting, using the xover and gain controls on the unit? However the THX setting which bypasses the xover and uses the preamp xover/gain seems a better match to my former LFE setting (except the gain which is still controlled in part on the L8400)

I don't have a THX pre-amp, can someone tell me what settings to use for my range of DD, DTS, SACD, DVDA material?

Thanks much

Congratulations. I have my EQ set on "Normal", Gain at "1-O'clock" & crossover on maximum "150-Hz". I have my Marantz AV-7005 Crossovers set as follows:
FL & FR at 40-Hz, Center, SL & SR at 80-Hz.

[JBLAddict]

Congratulations. I have my EQ set on "Normal", Gain at "1-O'clock" & crossover on maximum "150-Hz". I have my Marantz AV-7005 Crossovers set as follows:
FL & FR at 40-Hz, Center, SL & SR at 80-Hz.

thanks, I did an "AIX records cal disc" run using DD-TruHD 5.1 and LCPM 5.1 outputs:

got level matched 70dB w/ THX setting (disables sub xover/gain) drop my preamp (sub-LFE, FL/FR-full) gain down to -4 (of 10)
got level matched 70dB w/ Normal setting (enables sub xover-150Hz/gain-2'oclock) and raise preamp (sub-LFE, FL/FR-full) gain up to +6 (of 10)

I'm assuming ?? these are equal options except the Normal setting is capping the LFE pre-out to the sub at 150Hz?? OR should I run the THX setting, assuming the LFE output in the various formats may output >150Hz?

[jener8tionx]

Well, I've had no luck fixing my PS1400. I think I might sell that one for parts. Also, I can't afford to replace it, so I might just have to sell my working PS1400 book shelves and center chanel. Oh well.

[rpatt]

Well, I've had no luck fixing my PS1400. I think I might sell that one for parts. Also, I can't afford to replace it, so I might just have to sell my working PS1400 book shelves and center chanel. Oh well.

Sorry to hear that. I was pulling for you.

[JBLAddict]

I'm thinking of adding a second HTPS-400 to my Performance Series 5.1 to feed my addiction. Question: How does one go about calibrating the system with multiple subs? guessing this may be a rabbit hole type question, but appreciate some initial feedback.

Thanks

[rpatt]

I'm thinking of adding a second HTPS-400 to my Performance Series 5.1 to feed my addiction. Question: How does one go about calibrating the system with multiple subs? guessing this may be a rabbit hole type question, but appreciate some initial feedback.

Thanks

I'm planning on upgrading my Pre-Pro from the Marantz AV-7005 to the AV-8801. This will be an upgrade from Audyssey MultEQ XT to Audyssey MultEQ XT32 which handles two subs individually. Audyssey MultEQ XT and my Velodyne SMS-1 only have one channel for the sub and calibrate multiple subs as a whole.

[rdgrimes]

I'm thinking of adding a second HTPS-400 to my Performance Series 5.1 to feed my addiction. Question: How does one go about calibrating the system with multiple subs? guessing this may be a rabbit hole type question, but appreciate some initial feedback.

Thanks

It's entirely dependent on your setup hardware and software. Fortunately, subs aren't much affected by distances, as long as you don't create a big null in your listening position, its all good. Some folks have stacked the HTPS400 with good results too, but I prefer having subs spaced around the room.

Basically you're just creating more choices without much in the way of a downside, have fun.

[Mr. Widget]

I'm planning on upgrading my Pre-Pro from the Marantz AV-7005 to the AV-8801. This will be an upgrade from Audyssey MultEQ XT to Audyssey MultEQ XT32 which handles two subs individually.

While I could write a convincing "white paper" on the benefits of discrete subwoofer channels, I'm not sure that it will be that significant of an upgrade in terms of actual in room acoustic performance. I would tread very cautiously on this upgrade path. I doubt the audio circuits are significantly improved if at all, and personally I would go with a $1000 Anthem MRX-300 and it's ARC calibration over Audyssey. I would use the Anthem's line outs and a proper multi-channel amp. You do lose balance outputs, but I think the overall sonic benefits would outweigh this step backwards.

Now, if you love bells and whistles... that's another story. I am advocating a sonic performance based direction.

Back to the Off Topic at hand however, yes, I think going with multiple subs is always a good idea. They can all be paralleled and you will get most of the benefits... if the subs are dissimilar or the room quite peculiar separate control/processing of each may be important, but typically it is not that necessary.


Widget