# The bottom metal Plate of the new PMG Signature Preamp looks dirty **URL:** \ **Category:** Preamplifiers\ **Tags:** support\ **Created:** [August 29, 2025, 8:15am UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583 "2025-08-29T08:15:53Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Photoken](https://avatars.discourse-cdn.com/v4/letter/p/bbe5ce/32.png) [@Photoken](https://forum.psaudio.com/u/Photoken)\ **Post date:** [August 29, 2025, 8:15am UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/1 "2025-08-29T08:15:53Z")
I took delivery of the brand new PMG Signature preamp last week. The bottom metal plate looks used or old. Is this normal? New owners please check and let me know. This is not a deal breaker, but I never had new audio components with such dirty looking bottom. Attached is a photo of it. There are whole bunch of holes not used. I guess PS Audio came up with a universal bottom plate that fits all the new PMG components? ![PS Audio PMG Signature Preamp Bottom Photo](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/4X/d/c/7/dc779406a869a342379a6894b456d44d7bf588fd.jpeg) ---
**Author:** ![Philip\_Gan](https://avatars.discourse-cdn.com/v4/letter/p/aeb1de/32.png) [@Philip\_Gan](https://forum.psaudio.com/u/Philip_Gan)\ **Post date:** [August 29, 2025, 9:39am UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/2 "2025-08-29T09:39:21Z")
That doesn’t look right! Not on view but not a finish that I’d expect. ---
**Author:** ![scotte1](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/scotte1/32/147_2.png) [@scotte1](https://forum.psaudio.com/u/scotte1)\ **Post date:** [August 29, 2025, 11:05am UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/3 "2025-08-29T11:05:42Z")
Welcome. I would call PSA service department and arrange for a swap or a credit of some sort. Aesthetic or not, that’s not acceptable for what is supposed to be a brand spanking new piece of kit. I expect PSA will make sure you are satisfied. Please keep us posted about how this is resolved. ---
**Author:** ![Paul](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/paul/32/6_2.png) [@Paul](https://forum.psaudio.com/u/Paul)\ **Post date:** [August 29, 2025, 11:23am UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/4 "2025-08-29T11:23:54Z")
Yes, that is normal. Sorry. We stressed over this for quite some time but, in the end, figured that because t’s never actually visible it wouldn’t be a big deal. The metal process used to protect this plate from the elements isn’t the prettiest. It’s a kind of galvanizing process (of which I cannot remember the name). If you look at the plate in detail, notice all the marks which are the underside of PEMs-they are press in fasteners-and there are dozens of them. The punching and insertion process is pretty intensive and then the plate has to be refinished with that galvanizing process so it is conductive (for the ground plane) while at the same time protected from the elements. In any case, all that to say we couldn’t paint it because of its role in EMI so it looks kind of ugly. Thankfully it’s on the bottom. ---
**Author:** ![scotte1](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/scotte1/32/147_2.png) [@scotte1](https://forum.psaudio.com/u/scotte1)\ **Post date:** [August 29, 2025, 11:56am UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/5 "2025-08-29T11:56:19Z")
This surprised me. Appreciate the detailed explanation… Congratulations on the new line, Paul. ---
**Author:** ![msaladino22](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/msaladino22/32/127421_2.png) [@msaladino22](https://forum.psaudio.com/u/msaladino22)\ **Post date:** [August 29, 2025, 1:03pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/6 "2025-08-29T13:03:26Z")
Is this the same for all PMG line Paul? ---
**Author:** ![Paul](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/paul/32/6_2.png) [@Paul](https://forum.psaudio.com/u/Paul)\ **Post date:** [August 29, 2025, 1:27pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/7 "2025-08-29T13:27:33Z")
Yes. One of the ways we were able to keep costs and, hence, retail prices at bay (with an inch and a half thick front panel and all) is to make things like top covers, bottom covers, and front panels universal. That way we could take advantage of higher quantity pricing from the machine shops. So yes, all PMGs share many common parts including bottom plates. ---
**Author:** ![mp5310](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/mp5310/32/92067_2.png) [@mp5310](https://forum.psaudio.com/u/mp5310)\ **Post date:** [August 29, 2025, 1:56pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/8 "2025-08-29T13:56:24Z")
Why is the front panel an inch and a half thick? ---
**Author:** ![Paul](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/paul/32/6_2.png) [@Paul](https://forum.psaudio.com/u/Paul)\ **Post date:** [August 29, 2025, 2:23pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/9 "2025-08-29T14:23:20Z")
It’s how we were able to generate that beautiful swoosh on the front and its part of the design aesthetic. If you have a standard 1/8th or quarter inch front plate it’s basically a sheet of metal and aside from engraving or coloring there’s not much “sculpting” you can do for the unit’s visual appeal. I have always wanted a thick, machined, PS Audio swoosh to grace the front panel of our high-performance line but it’s incredibly expensive to do and so, up until a year or so ago, we were unable to pull it off. Since then, our amazing procurement genius, Alex, has figured out a way for us/me to have our/my cake and eat it too. Nice because it’s got my name on the front. 😊 ---
**Author:** ![RonP](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/ronp/32/213555_2.png) [@RonP](https://forum.psaudio.com/u/RonP)\ **Post date:** [August 29, 2025, 6:42pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/11 "2025-08-29T18:42:58Z")
I don’t think I ever purposefully looked at any bottom plate. Now I won’t for sure for fear of what i might see. ---
**Author:** ![Photoken](https://avatars.discourse-cdn.com/v4/letter/p/bbe5ce/32.png) [@Photoken](https://forum.psaudio.com/u/Photoken)\ **Post date:** [August 29, 2025, 9:55pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/12 "2025-08-29T21:55:06Z")
Hi Paul, Thanks for the reply. The PMG Signature Preamp is my first gear from PS Audio. I am also a brand new member to the PS Audio family and the forum. I enjoy watching your YouTube videos. Keep them coming. ---
**Author:** ![Paul](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/paul/32/6_2.png) [@Paul](https://forum.psaudio.com/u/Paul)\ **Post date:** [August 30, 2025, 11:59am UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/13 "2025-08-30T11:59:48Z")
Thanks and welcome! ---
**Author:** ![NipperDog](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/nipperdog/32/179189_2.png) [@NipperDog](https://forum.psaudio.com/u/NipperDog)\ **Post date:** [August 30, 2025, 7:46pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/14 "2025-08-30T19:46:42Z")
I’ve been in this hobby for over 50 years, and I don’t think I’ve ever thought to look at the underside of _any_ component I’ve owned. 🤔 ---
**Author:** ![kerosene](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/kerosene/32/9084_2.png) [@kerosene](https://forum.psaudio.com/u/kerosene)\ **Post date:** [August 30, 2025, 8:27pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/15 "2025-08-30T20:27:24Z")
I doubt I would have ever looked at the bottom. Now, I’m going to look at the bottom plates of all my components. ---
**Author:** ![scotte1](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/scotte1/32/147_2.png) [@scotte1](https://forum.psaudio.com/u/scotte1)\ **Post date:** [August 30, 2025, 8:54pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/16 "2025-08-30T20:54:12Z")
Don’t do it! 😜 ---
**Author:** ![Elk](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/elk/32/1240_2.png) [@Elk](https://forum.psaudio.com/u/Elk)\ **Post date:** [August 30, 2025, 9:02pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/17 "2025-08-30T21:02:35Z")
I have seen the underside only of tube equipment. And then only because I was curious to see what was inside and how it was wired. As it turns out, I am glad the topic came up here. Interesting. ---
**Author:** ![fvector750](https://avatars.discourse-cdn.com/v4/letter/f/d6d6ee/32.png) [@fvector750](https://forum.psaudio.com/u/fvector750)\ **Post date:** [August 30, 2025, 10:43pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/18 "2025-08-30T22:43:14Z")
I’m not trying to make light of the OP’s concern or anything like that at all because I would have gasped as well. It just made me chuckle a little bit because sometimes I observe that we audiophiles are a funny bunch. We purportedly strive for the perfect sound and nothing else. And yet, we all seem to be chasing this idea of organic sound with this crazy dream of emulating very imperfect analog gear with the most cutting edge microprocessors. The funny thing in all of this is that we can’t stand the sight of “organic” material. One side of my brain is shouting at me to look at it differently and appreciate the patina as art. ---
**Author:** ![roninaudio](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/roninaudio/32/262996_2.png) [@roninaudio](https://forum.psaudio.com/u/roninaudio)\ **Post date:** [August 30, 2025, 11:25pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/19 "2025-08-30T23:25:02Z")
Sounds like a robust process unique to PSA. Not attractive but functional. Kinda reminds me of Lyle Lovett….. ---
**Author:** ![dchang05](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/dchang05/32/294697_2.png) [@dchang05](https://forum.psaudio.com/u/dchang05)\ **Post date:** [August 30, 2025, 11:44pm UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/20 "2025-08-30T23:44:10Z")
The bottom plate of Grimm MU2 is as beautiful and clean as the top, I know because I needed to install internal SSD that they forgot to install. I have never seen the bottom plate of my Gryphon D333, and I never will. ---
**Author:** ![falling\_leaves](https://avatars.discourse-cdn.com/v4/letter/f/a9adbd/32.png) [@falling\_leaves](https://forum.psaudio.com/u/falling_leaves)\ **Post date:** [August 31, 2025, 12:48am UTC](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583/21 "2025-08-31T00:48:28Z")
Not sure if this is one of those penny pinching decisions, I don’t remember the last time I see this “dirty” bottom plare from any manufacturers at any price. A bit disappointed to see this from PSA, especially the founder series and especially at $8k price. [Next page](https://forum.psaudio.com/t/the-bottom-metal-plate-of-the-new-pmg-signature-preamp-looks-dirty/42583.md?page=2)