Crown XLS- for the rest of us!

Odal3 · « **Reply #1620 on:** 15 Feb 2017, 08:01 pm »

Could it be the internal fan?

dimedrol · « **Reply #1621 on:** 15 Feb 2017, 09:51 pm »

no fan I have ever heard emits 15khz hiss. More sounds like electrical noise. But folks, could you check your own crown to see if there's any noise at all, or is everybody saying theirs are dead silent? That I can hardly believe, because every single switching power supply I've ever had hissed, some more, others less.

Panelhead1 · « **Reply #1622 on:** 16 Feb 2017, 04:46 pm »

I misunderstood your issue. Thought you were getting noise from the speakers. Mine are at the bottom of a heavy wood rack. Will get down and listen.
The chokes may be singing. Folsom recommended dampening them with a resistor to prevent this. Think a 2k, 5 watt was his choice here. He may contribute his thoughts.
I have heard diodes make this noise in tube amps. Especially after replacing a one amp bridge with a three amp. Folsom replaced the stock diodes when he offered mods for the Crown units. Said the diodes was a lot of work.
The flimsy chassis was a concern. Damped the lid and chassis. Snubbed the filter caps, and damped the chokes in both of my units. One or all these changes may lower the physical noise generated.

Panelhead1 · « **Reply #1623 on:** 17 Feb 2017, 04:30 am »

Played a little music and turned volume off the listen to unit for mechanical noise. None.

seikosha · « **Reply #1624 on:** 17 Feb 2017, 01:39 pm »

Quote from: dimedrol on 15 Feb 2017, 09:51 pm

no fan I have ever heard emits 15khz hiss. More sounds like electrical noise. But folks, could you check your own crown to see if there's any noise at all, or is everybody saying theirs are dead silent? That I can hardly believe, because every single switching power supply I've ever had hissed, some more, others less.

Even if everyone's unit was emitting a 15khz hiss, most can't hear that high and would swear that their unit was dead silent. I'd probably be one of them. That's the upper limit of my hearing last time I checked.

dimedrol · « **Reply #1625 on:** 17 Feb 2017, 08:01 pm »

I opened the cover and listened closely - it's the transformer that the noise is coming from. It is much more pronounced with the cover open. Since it's high pitched, those frequencies are easily absorbed with any kind of shield, so I just went ahead and duct-taped 50% of the front panel vent holes. That has significantly reduced the audible noise. Considering I'm only using 1/5 of the amp's power, I think it won't burn the house.

Armaegis · « **Reply #1626 on:** 17 Feb 2017, 10:17 pm »

Maybe just put a small throw pillow in front of the amp? That should absorb a good chunk of the sound and not block your ventilation.

dimedrol · « **Reply #1627 on:** 21 Feb 2017, 01:49 pm »

so this one here sings pretty badly

I thought it was the transformer that hissed, but it wasn't. It's the choke. Any helpful ideas on how to tame it?

Panelhead1 · « **Reply #1628 on:** 22 Feb 2017, 02:47 am »

Try mechanical dampening. A cork cabinet door bumper might be perfect. Look at Ace or another full service hardware store.

Armaegis · « **Reply #1629 on:** 22 Feb 2017, 03:11 am »

If it doesn't have any heat, I'd be tempted to just glob hot glue over it.

dimedrol · « **Reply #1630 on:** 22 Feb 2017, 10:00 am »

folks on diyaudio suggested that the hiss may be a consequence of an upstream problem, so it's worth to do some checks there before acoustically dampening the choke. I decided to sent it for repair to people with an oscilloscope. Hopefully it's just the choke that is faulty in which case a local fix will suffice.

Jazzaudio · « **Reply #1631 on:** 4 Mar 2017, 05:43 pm »

Is Salis Audio still around and cryoing amps?

guest61169 · « **Reply #1632 on:** 20 May 2017, 07:43 pm »

Quote from: dimedrol on 22 Feb 2017, 10:00 am

folks on diyaudio suggested that the hiss may be a consequence of an upstream problem, so it's worth to do some checks there before acoustically dampening the choke. I decided to sent it for repair to people with an oscilloscope. Hopefully it's just the choke that is faulty in which case a local fix will suffice.

So what was the resolution for this issue?

mosawdust · « **Reply #1633 on:** 21 May 2017, 01:56 pm »

I want to thank everyone who participated in the post and all the testing. I read through every post a couple of times and decided it was time for me to jump on board. I ended up with a pair of XLS1502's running in bridged mode to power my VMPS ST/R's and I can say I'm a happy camper. These are going through a CA integrated as my pre which is working decently. Thanks to everyone for the great efforts and testing.

MindRise · « **Reply #1634 on:** 27 Feb 2018, 11:51 pm »

I have the XLS-1502, I'm curious if these will fit

https://www.ebay.com/itm/PURE-COPPER-Speaker-Amplifier-Binding-Post-Connectors-MADE-IN-UK-Two-Pair/173129386674?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

kane · « **Reply #1635 on:** 12 Mar 2018, 05:32 am »

Has anyone checked out/ used the Crown XLC series??

It is apparently XLS without AD/DA conversion inside. Sounds like XLS qulity at lower price.

Armaegis · « **Reply #1636 on:** 22 Mar 2018, 06:56 am »

Has anyone here had experience with the QSC PLD lineup? It's not Crown, but I figure this thread might contain the only people who would have experience with it.

Right now I've got a PA rig (bi-amped tops and subs) that I haul around with a stupid heavy trio of Yamaha P7000s. I'd really love to reduce the weight/size down to 4U and save my back, but the options out there seem limited and I don't have the money to spend on Powersoft amps (though I do drool over the 1U 4-channel amps). Must have 4pole speakons at the back.

celo · « **Reply #1637 on:** 22 Feb 2019, 06:30 pm »

What a long thread!

I know I am doing a shortcut but I have few questions.

1-Salis Audio is gone and it is Folsom, yes?
2-Is this the DriveCore or the current DriveCore 2 amp we are talking about?
3-Is the gain adjustable with this amp?
4-Anybody still do mods to this amp and if so what are these mods?

I have never heard DriveCore before. I have had TI TPA3116/18.
They were good but not Tripath good.
So, when looking for a comparable chip to Tripath sound, someone said Crown DriveCore amps. That’s how I ended up here:)

cubiclecrush · « **Reply #1638 on:** 29 Jun 2020, 07:42 pm »

Quote from: barryso on 28 Mar 2015, 02:28 am

Everyone who claimed the speaker connectors are poor were right on the money. After doing a lot of listening I put the bare cables into speakon connectors. Immediately noticed the mids and treble cleaned up considerably. The tonality is better and a lot of grunge is gone. It makes little sense as it added an additional connector in the signal path but it made quite a nice improvement.

Before the speakon connectors I was going to say the mids and treble were OK and fairly grain free but not clean enough for a long listening session. The speakon connectors take it up at least a few steps. The mids and highs are more to a level you'd expect in a more expensive amp and it sounds good.

No, the speakons didn't add the harmonic richness of a tube amp but they made a pretty astounding improvement. I wouldn't have the right impression of the amp if this thread hadn't pointed out the connectors need help.

Wow - I'm loving the switch to Speakon cables for my XLS1500! I got some custom speaker cables at a reasonable price and I think it cleaned up the sound from when I was using the regular binding posts.
https://www.performanceaudio.com/custom-cables-speaker-cable-made-from-canare-4s11-speaker-wire.html

Next I might try a balanced passive preamp with XLR connections....but one step at a time.

Satriany.powa · « **Reply #1639 on:** 13 May 2023, 05:03 am »

Hello,

I was wondering if there has been a recent comparison between last version of crown xls and Yamaha px series and ncore series but only to drive subwoofers? Like 15" heavy woofer...

Regards Greg

Crown XLS- for the rest of us!

guest61169