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Denon DP-400 Turntable has no treble

GXAlan

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Oh, the other thing to note is that the database shows that most LPs can get into the 16 kHz range easily, so the muted treble is not what you'd expect from vinyl as opposed to digital.

 
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BullBuchanan

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Forget about the old Shure! It might be bad Get a a present day cheap cartridge and wire the system correctly as suggested several times and try again.
Suggestions without evidence or justification aren't really my thing. I would think that would be commonplace on a science forum.

The stylus is a modern design that's well regarded from what I can see and brand new. unless I'm missing something that no one has explained, except the bit about capacitance, the cartridge used shouldn't matter very much, should it? As for the wiring, has someone suggested the system isn't wired correctly currently? Is it a complex thing? My my eyes all there is are two wires going from cart to stylus and the RCA cables going out from the pho jack.

If you have information to share I'd love to hear it though.
 
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BullBuchanan

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The Shure M91ED requires capacitance between 300 - 500 pf. It will sound somewhat dull if your capacitance is much less. You can add capacitance.
I searched around the forum and google but couldn't find much on modifying capacitance. It seems it's a buit of a dark art and manufacturers don't like to share the expected capacitance of their input and that includes denon who doesn't have it on their x3700h spec sheet for the phono preamp.
 

Robin L

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I got my first Shure 91 series back in 1973. It's no longer in production. Shure is no longer in the phono cartridge business. They stopped making phono cartridges and styluses in 2018. Get the Audio Technica and save yourself some grief.
 

Balle Clorin

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Suggestions without evidence or justification aren't really my thing. I would think that would be commonplace on a science forum.

The stylus is a modern design that's well regarded from what I can see and brand new. unless I'm missing something that no one has explained, except the bit about capacitance, the cartridge used shouldn't matter very much, should it? As for the wiring, has someone suggested the system isn't wired correctly currently? Is it a complex thing? My my eyes all there is are two wires going from cart to stylus and the RCA cables going out from the pho jack.

If you have information to share I'd love to hear it though.
I as others proposed in earlier post that the wiring/connection to from RIAA was possibly wrong, suggesting RIAAs connected in series. If the amplifier line up is correct the fault would be in the cartridge . I have som old Shures and that where too old to work properly, very strange sound and poor Tracking ( one was Shure V15 type 5 HE original not used since purchased in 80s) , putting on a cheap AT 3600 proved to me that the fault was the cartridge not my system . It is just a matter if troubleshooting and elimination.

If you have the same poor sound with a AT91E ( less VFT and less damaging to your records than 3600) or some other cheap cartridge your problem is in the Amplification chain. Mats, tracking angle and cartridge type/maker VTF difference does not make it sound so bad as you describe .

What input are you using on the amplifier?
Is it a MM/MC switch/button somewhere?
If you are bypassing the internal RIAA in the turntable you should use the MM setting and connect to the Phono Input on amp. If you are using the TT internal RIAA connect to the Amplifiers CD/line input .


As bad as you describe it fiddling with Capacitance setting/loading will Not help on a major issue
Tell us how it goes…
 
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Chrispy

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Suggestions without evidence or justification aren't really my thing. I would think that would be commonplace on a science forum.

The stylus is a modern design that's well regarded from what I can see and brand new. unless I'm missing something that no one has explained, except the bit about capacitance, the cartridge used shouldn't matter very much, should it? As for the wiring, has someone suggested the system isn't wired correctly currently? Is it a complex thing? My my eyes all there is are two wires going from cart to stylus and the RCA cables going out from the pho jack.

If you have information to share I'd love to hear it though.
What if the cartridge body is at fault, tho? It's pretty old....
 

GXAlan

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Suggestions without evidence or justification aren't really my thing. I would think that would be commonplace on a science forum.

I see it as trouble shooting.

“The bushing that supports the stylus is made of a flexible material and will harden over time due to the ozone in the atmosphere.”

Any time you are dealing with vintage gear, it’s important to figure out if that’s the culprit. The seller may be accurate in terms of play time, but how the stylus was stored could impact the sound.

If you've tried the list of things listed here, please update us. We're here to help.
 
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BullBuchanan

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I see it as trouble shooting.

“The bushing that supports the stylus is made of a flexible material and will harden over time due to the ozone in the atmosphere.”

Any time you are dealing with vintage gear, it’s important to figure out if that’s the culprit. The seller may be accurate in terms of play time, but how the stylus was stored could impact the sound.

If you've tried the list of things listed here, please update us. We're here to help.
I'll do that, thanks. Quick question though. It says in that article that "replacing the stylus returns the cartridge to its original condition". Wouldn't that apply in this case?

It seems the universal response is to get a new cartridge, so I'll probably either do that or just get a different table that has a different cart on it as that might be more economical.
 

LTig

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I'll do that, thanks. Quick question though. It says in that article that "replacing the stylus returns the cartridge to its original condition". Wouldn't that apply in this case?

It seems the universal response is to get a new cartridge, so I'll probably either do that or just get a different table that has a different cart on it as that might be more economical.
No, first you should change the wiring as described in post #9 as it's quick to do and costs nothing.
 
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BullBuchanan

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I as others proposed in earlier post that the wiring/connection to from RIAA was possibly wrong, suggesting RIAAs connected in series. If the amplifier line up is correct the fault would be in the cartridge . I have som old Shures and that where too old to work properly, very strange sound and poor Tracking ( one was Shure V15 type 5 HE original not used since purchased in 80s) , putting on a cheap AT 3600 proved to me that the fault was the cartridge not my system . It is just a matter if troubleshooting and elimination.

If you have the same poor sound with a AT91E ( less VFT and less damaging to your records than 3600) or some other cheap cartridge your problem is in the Amplification chain. Mats, tracking angle and cartridge type/maker VTF difference does not make it sound so bad as you describe .

What input are you using on the amplifier?
Is it a MM/MC switch/button somewhere?
If you are bypassing the internal RIAA in the turntable you should use the MM setting and connect to the Phono Input on amp. If you are using the TT internal RIAA connect to the Amplifiers CD/line input .


As bad as you describe it fiddling with Capacitance setting/loading will Not help on a major issue
Tell us how it goes…
Thanks for the info. Just to clarify, because I mentioned it, but removing the acrylic mat and redoing the the VTF adjustment had a massive improvement, so I'm getting closer to something decent now. I'll definitely look at getting one of those other cartridges though, as it seems the capacitance issue is a potential problem that can be difficult to confirm.


As for the setup:
I'm using the phono input on the receiver with the built in pre-amp disabled. there' not configuration for MC vs MM, just a preamp on/off switch and a button to enable/disable the autostop. There's only one set of RCA outputs on the back of the TT so you use the same if you're using the built in pre-amp or not,

When we're talking about cartridges, I know a lot of people talk about cartridge + stylus together/interchangeably. Just a reminder that in this case while the cart is presumably old, the stylus was manufactured at some point in the last 2 years. It's my understanding that VTF requirements are driven by the stylus, not the cart. Is that correct? I'm definitely not against trying a new one, but I just want to do it for the right reasons and understanding all the variables in play between a given cartirsidge as the stylus that I end up pairing it with. I think in the case of the audio technica recommendations above I'd be repalcing both at the same time.
 

GXAlan

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there is are two wires going from cart to stylus and the RCA cables going out from the pho jack.

Can you post a picture? What about the cartridge to the tonearm?
 

Thomas_A

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Suggestions without evidence or justification aren't really my thing. I would think that would be commonplace on a science forum.

The stylus is a modern design that's well regarded from what I can see and brand new. unless I'm missing something that no one has explained, except the bit about capacitance, the cartridge used shouldn't matter very much, should it? As for the wiring, has someone suggested the system isn't wired correctly currently? Is it a complex thing? My my eyes all there is are two wires going from cart to stylus and the RCA cables going out from the pho jack.

If you have information to share I'd love to hear it though.
There should be four wires from tonearm to cartridge. Stylus should just be inserted into the cartridge body.
 
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BullBuchanan

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Can you post a picture? What about the cartridge to the tonearm?
I was mistaken. There are indeed 4 wires from the tonearm. At any rate, it seems using the built in preamp is offering an additional improvement over the one in my amp (surprisingly). There's quite a bit less noise now. I was previously hearing crackle out of my speakers even with the tonearm docked and now it's dead silent. Kinda surprising as most folks recommend bypassing built in preamps, but maybe the Denon implementation is just a bad fit for the load.

PXL_20231204_074002667.NIGHT.jpg
 

audio_tony

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The Shure M91ED requires capacitance between 300 - 500 pf. It will sound somewhat dull if your capacitance is much less. You can add capacitance.
No. More capacitance = less treble with most magnetic cartridges that I've worked with in the past (and that's many).

The old Ortofon FF15E for example had an add on called the 'Cap 210' which was a 210pF capacitor that fitted between the cartridge terminals. This was intended to reduce a strident top end.
 

stoo23

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Whilst I am doubtful the 'in-built' pre amp is going to provide Super Hi end audiophile quality, I am thinking as others have suggested, utilizing it, may be a better option. Although, that said, it seems the Original cartridge (as fitted), to this Denon was the Denon 9410037907 see here: https://denon.encompass.com/item/12429230/Denon/00D9410037907/ which may actually have been manufactured by Audio Technica and has similar specs to the AT91.

Also, I think the issue may be as suggested previously, an incorrect Capacitance or Load issue.
From what I can ascertain, the Original Cartridge wanted to see a load capacitance of 100-200 pF and a load impedance of 47,000 ohms.
The suggested AT95 series has Identical Load requirements to the Original Cartridge.

Shure’s recommended capacitive load for the M91E and M91ED is in the range of 400-500 pF !! I'm not sure about it's desired impedence but is probably similar.

It's probably safe to assume the 'in-built' pre amp is providing an input for the Original cartridge that is ideally suited and happy with, whereas Not so with the Shure.
Difficult to say What Load variance would be seen when switching the in-built EQ module Off AND what loads Your amplifiers Phono Input would be providing.

BTW, I'm 68 and I used to sell the Shure M91, Way back when I used to sell HiFi in my late teens and early 20's !! and whilst acceptable, it was not that spectacular, or note worthy lol there were Many better cartridges.

It may be best (as others have suggested) to 'Ditch' the Shure and get an Audio Technica that will be Happy 'Seeing' the in-built pre amp :)
You'll probably get Good Money for the Shure on Ebay :)

What Amp are you using ??
 
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JeffS7444

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Shure M91 ought to have decent resale value as a DJ cartridge, but even the pricier M97xE had non-flat frequency response:
https://hometheaterhifi.com/reviews/vinyl/turntable-accessories/shure-m97xe-phono-cartridge-review/
Of course it helped that most hifi systems of the era had tone controls!

For the more technically minded, Rod Elliott has written a good article on how MM phono cartridge loading works:
https://www.sound-au.com/articles/cartridge-loading.html

If the built in phono preamp of the Denon is anything like the one built into my Hanpin-built Audio Technica, it may actually be pretty decent, but capacitance may be very low.
 
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Balle Clorin

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Just a reminder that in this case while the cart is presumably old, the stylus was manufactured at some point in the last 2 years. It's my understanding that VTF requirements are driven by the stylus, not the cart. Is that correct
Shure stopped making stylus and cartridges years ago. A new third party replacement stylus less than 2 years old should sound fine unless it is A dud, that happens. VTF is A function of the stylus and needs correct compliance to align correctly with the coils. the cartridge it self rarely goes bad, I have got 40+years old cartridges that sound fine with a new stylus ( AT95E)
 

JP

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No. More capacitance = less treble with most magnetic cartridges that I've worked with in the past (and that's many).

It can in cases of extremely high capacitance where an RC LPF is formed, but in most cases it'll cause an HF peak due to LC resonance. The more L or higher C the lower the resonant f, which will often push the peak in to the audible range. The below plot is rather typical:

VM740ML_vs_VM95ML_47k_STR_100.png
 
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