Pass labs X350.5 jumpers and Power cables

I just picked up a Pass labs X350.5. Aside from an annoying ground loop I left left to figure out it sounds very nice.

The Pass Labs web site appears to be down. I've tried all morning to ask this question.

I want to try some single ended cables I have but read somewhere that I would need jumpers of some sort, I'm assuming, on the input side of the balanced connections. Was this amp supposed to come with jumpers?

This was a buy gone miserable. The was supposed to be nearly new, not even broken in. Upon receiving this amp I noted a lot of scuff marks, a few scratches and considerable dirt and dust. Not exactly an 9/10! I digress.

I noted substantial differences rotating power cables. Is there a general rule of power cable when it comes to this amp?

The amp comes with jumper pins for the XLR connections if single ended connections are used. The ground configuration is from pin one to three. In a V configuration. The pin to the top right will be number one. The pin to the top left will be number two. The bottom pin will be number three. I use a Shunyata Python CX with my 250.5 with stellar results. I hope this helps ... Zenieth
Great Zenieth, this totally helps. Pass website is still down.

I'm using the following power cords as I remember;

DIY VH-Audio Flavor 4 (4 twisted 12 ga wires with a reverse twist ground around the 4 + and - wires terminated with Furutech FI 11 gold connectors

Acrolink 6N-P4030 terminated with Oyaide P079 connectors

Neotech NEP-3001 terminated with Furutech silver FI-25M

Very different presentations with the Acrolink being the clearest but needing some tube rolling on the preamp to get some low end response. The Flavor 4 was the warmest and great with most material. The Neotech was a blend of both speed and somewhat lacking in bass compared to Flavor 4 and not as clean in the highs as the Acrolink.

It's still early so all with a grain of salt.
When I got my second Pass amp, the jumpers were missing. The kind people at Pass sent me some, free of charge. Cardas also makes jumpers, if you feel the need to pay for them.

Like Zenieth, I use a Shunyata Python with my amp.

Sorry to hear your experience so far has been frustrating. Hopefully, you will like the X350.5 with your system. IMO, it's a great amp.
Playing with the system last night I was rotating interconnects and power cables looking for a good balance and what the Pass is doing in my system. A few quick observations. I cannot get the bass where I want it. This could be part of the Dynaudio C1's character and I was hopeful that the Pass's current would solve some of the woolliness, and it did to a certain extent. My ears are still accustomed to the line arrays which do bass. Oh my do they do bass. And they do it with lots of drivers.

I tried plugging the Pass straight into the wall, bypassing the Power Plant Premier. I think I like it better without a regenerated AC. I'll have to revisit that scenario.

The C1's I think sound better with the Pass than do the line arrays. The Nuforces through the Power Plant Premier to the line arrays was breathtaking at times. I could have left well enough alone.

I'll check room response today with some RTA software and a mic. I can see a second sub in this system.

The front panels of the amps are pretty beat up. I wonder if Pass doesn't refurbish front panels?

Thanks for your opinions.
The Pass has excellent bass quality, but everything matters. Your speakers, Amps, cables , power source etc.

IMHO, The Pass works better with unresricted power.
Please do not plug it into the PS audio Equipment.
Dedicated line also would help, but if not possible, limit the amount of items on the line that the Pass Amp is plugged into.
I also confirm that Shunyata Anaconda or Python work good with Pass amps. In addition, I had quite satisfactory result with Exact Power EP-15A.(AC Regenerator-filter)
I also recommend XLR cable use over RCA.
You can make those jumper pins yourself. Just grab some solid-core copper cables and cut a piece, strip any outer jacket, and bend it into an "U" shape. When my house was under remodel, I found tons of 12 gauge ground wires that my contractor was throwing away, so I just pick them up to be used for situations like this.

Pass amps have one of the best bass control, or I should say most realistic bass rendition, I've heard.

I am using a BMI Orca II Limited Ed. powercord. My buddy also uses one of the Shunyata snakes on his with a pair of Dynaudio C4s. It took him a long time to get the bass dialed in. But they sound incredible right now.

After some experimenting last night I found that the Pass plugged into the wall, a dedicated circuit using 10awg copper with a Furutech outlet sounded superior to the PS Audio PPP. Thanks guys for the confirmation.

Too bad about the balanced interconnects sounding superior to the single ended. I hope to prove that wrong as I wish to use the balanced outs on my Cary SLP-05 pre to the Fathom F113's and the single ended cables to the Pass. Having mostly home brews but of significant quality, I'll be rotating cables until I get a handle on what I'll need to further the SQ.

Anybody want to drop by with some cables ;-)?

I made some crude jumpers last night and used my DIY RCA's which sounded great. I tried another pair and whooah sounded like crap. I mean crap. I went to the back of the amp and noted that one of my jumpers fell out. Now I know what jumpers mean to this amp!

What I'll do today is to grab some gold pins from a Burndy trim trio connector and 3 twists of 24awg gold plated jewelery wire and make some jumpers. I try that against the simpler 12awg copper approach.


As the night wore on and I played with setup on the system and sub I found a really nice balance and settled in to some of the best sounds I've heard. I took a room measurement using the Mobile USB Pre and RTA software and saw an amazingly flat response. 1 dip at about 180hz with a slight bulge at around 50 which I could dial down with the Fathom. But generally flat from 20Hz to 20KHz where it dropped very suddenly. It seems the Esotar tweeters I'm guessing don't sing beyond 20Khz?

I've got some very nice power cables but not of the cost of the Shunyata's. Looks like I'll be looking at the used market soon for a power cable.
Dont use the balanced outs to a subwoofer.

I am using the RCA outs from my Preamp to the Fathom F113's . The Balanced outs go to my Pass Labs Amp.
You really should try this.
Actually, the Balanced is a ittle louder than the single ended and does IMHO provide a more fuller sound.
The Fathom F113's can always be turned up if need be.
Ozzy, it's the setup I have now. JL Audio greatly prefers balanced and now it seems Pass prefers balanced as well. Well, Pass wins.
Desalvo55 - I'm sure you can get a new face plate (or just the handles - depending on what is scratched) from Pass Labs. Replacing them is not difficoult at all. If the amp was rated 9/10 cosmetic coindition, I would seek compensation from the seller.

Overstating the cosmetic condition is becaming a norm on AgoN lately - unfortunately.
I called Pass yesterday regarding the cost of the faceplates. Easy to replace I'm sure but at what cost. I need to more aware of feedback score when there is none. Told that this amp wasn't even broken in and looking like it's been around for a long long time leaves tuning somewhat difficult. If I'm selling this amp it's a 7/10.

I tried Steve Vai "Fire garden" last night as well as Steve Winwood "Nine Lives". What I find is a suprising amount of "hardness" in the treble for lack of better term. Sound didn't seem balanced especially if I attempted higher volumes. Switching to Neil Young "Chrome Dreams II" yielded much better results. This is balanced out from my Cary. Haven't tried tube rolling yet as I like to start with power cables then interconnects. I only have 1 set of balanced cables which worked wonders with my Nuforces but this is a far different animal.

No doubt Shunyata is the popular choice for power. What about interconnects?
Easy to replace I'm sure but at what cost.

Are you sure you need a complete faceplate ? The 'faceplate' consists of 3 separate parts - the actual faceplate, left 'handle' and right 'handle'. Maybe it is enough to replace just one of them, or both - they cover almost 2/3 of the faceplate. Take a closer look.
I just need the front handles and not the actual faceplate. The handles are $90 dollars a pair- reasonable enough for what they are.

It's not that they are altogether bad, just way short of what I expected.
$90 for a pair is well worth it IMO. You will loose much more than $90 in resale if you list the amp as 7/10, instead of 9/10 (after replacing the handles).
Last night I began again tweaking this system. I had to accept earlier that the Nuforce 9SEV2 Cary Preamp & LS6 combo was nothing short of great in our room. Now I spent x 2 on speakers and a Pass that was good but not great.

Audio is funny though. I've been in many rooms where the equipment was amazing and the sound not. I attribute that to the differences in the way we hear sounds physically and emotionally. I try to mimic as much as possible the sound of live and work from there. I'm very finicky and rather obsessive about what I hear and generally concede that what I have will have its issues. Where am I going?

Lots of opinions about power cables. They make a difference to anyone who isn't tone deaf and I believe are part of tuning a system, just like the interconnects.

Ah the interconnects. I stuck with balanced as a few members mentioned to stay that route. Make second set of DIYers were broke (fragile as hell) but always sounded amazing so I again repaired the broken ground and went back to single ended. Jumpers in place (the 12awg wire variety) we sat down to listen. What I was greeted with was the best sounds I've ever heard drifting through our room and maybe through any room. What was on cue was REM Automatic For The People, first cut. Company showed up and I pushed her to the sweet spot "listen to this". She was spellbound as was I. I replayed the same cut again for my wife unit. But company conversation took over and I had to wait.

Next up was Annie Lennox "Medusa" a very familiar disk I've been referencing for many years. It was absolutely stunning. Every cut was a marvel of balance, ambiance, detail, holographic imagery. I felt like I was hallucinating. How the hell can an interconnect make such an astounding difference? And seemingly the wrong interconnect for this amp.

I went to bed last night and told my wife, "OK maybe now it was worth the money". She agreed ;-)