Another AVR/Phono Preamp Question

Tuneaholic

Tuneaholic

Audiophyte
I have a Denon AVR 2500 (dedicated phono input) and Denon DP 400 turntable (AT VM95ML and Grado Red carts). Both TT and AVR have phono pre amps built in and I currently have the DP 400 “off” and run through the AVR phono input (preamp) which sounds slightly but noticeably better.

Would it be cost effective to spend $200 or so on a dedicated phono pre amp to try and improve the sound playing LPs?

Looking at iFi Zen Phono or Schiit Mani 2 preamps.

Speakers – Monitor Audio Silver 200 6g mains, Elac Debut 2 5.2 Center and Surrounds, and Klipsch R-10 Sub
 
TLS Guy

TLS Guy

Seriously, I have no life.
I have a Denon AVR 2500 (dedicated phono input) and Denon DP 400 turntable (AT VM95ML and Grado Red carts). Both TT and AVR have phono pre amps built in and I currently have the DP 400 “off” and run through the AVR phono input (preamp) which sounds slightly but noticeably better.

Would it be cost effective to spend $200 or so on a dedicated phono pre amp to try and improve the sound playing LPs?

Looking at iFi Zen Phono or Schiit Mani 2 preamps.

Speakers – Monitor Audio Silver 200 6g mains, Elac Debut 2 5.2 Center and Surrounds, and Klipsch R-10 Sub
I doubt you will hear a difference. The RIAA Eq circuit is simple and not complex. Some do manage to get it wrong apparently. I suspect that the difference you are hearing is in gain structure, unless your TT has a very inferior IC chip.
 
Swerd

Swerd

Audioholic Warlord
Would it be cost effective to spend $200 or so on a dedicated phono pre amp to try and improve the sound playing LPs?
I agree with TLS Guy. Buying an external phono pre amp would be a waste of $200. Spend that money instead on more music.
 
TLS Guy

TLS Guy

Seriously, I have no life.
I agree with TLS Guy. Buying an external phono pre amp would be a waste of $200. Spend that money instead on more music.
I have had one more thought about this, that has not occurred to me before. MM cartridges are designed around the usual capacitance of cable to preamp/amp. What I mean by this is the capacitance of the cable connecting TT to amp is a crucial factor on TT reproduction. As I have stated before I optimize the loading capacitance of any given cartridge. I suspect this in not factored in in TTs with a built in phono preamp. So there is every possibility that the loading capacitance is too low. This affect is likely to be audible, in that using the TT preamp, rather then the receiver preamp could well result in excess HF and give a harsher sound.
 
Swerd

Swerd

Audioholic Warlord
MM cartridges are designed around the usual capacitance of cable to preamp/amp. What I mean by this is the capacitance of the cable connecting TT to amp is a crucial factor on TT reproduction.
Isn't that a factor of that cable's length? Older TTs came with 36-39" long cable (1 yard to 1 meter) hard wired to the TT. And owners were warned to avoid using cable extenders.

The photo of the rear panel of the Denon DP400, shows a pair of RCA jacks and a switchable phono equalizer. I believe Denon provided a MM pickup with this TT, but did Denon also provide a cable? What length? (Edit: I just read that Denon supplies a 39" RCA cable.) Does Denon also include adequate instructions as to how this cable's length may be longer only if the built-in equalizer is used?
1656780506988.png

As I have stated before I optimize the loading capacitance of any given cartridge. I suspect this in not factored in in TTs with a built in phono preamp. So there is every possibility that the loading capacitance is too low. This affect is likely to be audible, in that using the TT preamp, rather then the receiver preamp could well result in excess HF and give a harsher sound.
If it isn't factored into the TT's built-in phono pre-amp, why would you expect it to be different with his AVR's phono pre-amp, or an external one?
 
Last edited:
O

OHMisback

Audioholic
I have a question. Are you plugging the TT into an AUX input or or leaving it plugged into the TT input, when you use the onboard TT amp? Normally MM carts do not require additional loading. The cable is very important, shorter is better. MC or some MI carts, cables and SUT cables are a great place to make or break a great setup.
You have to load them correct. I use modified Male RCAs for loading or you can solder them in place. Herron makes an assortment at a reasonable price. Quality parts always, with that guy.. Great source of accurate information too.

He use to make one of the best phono stages around for the money. Great preamp and SS amps too.

Regards
 
TLS Guy

TLS Guy

Seriously, I have no life.
Isn't that a factor of that cable's length? Older TTs came with 36-39" long cable (1 yard to 1 meter) hard wired to the TT. And owners were warned to avoid using cable extenders.

The photo of the rear panel of the Denon DP400, shows a pair of RCA jacks and a switchable phono equalizer. I believe Denon provided a MM pickup with this TT, but did Denon also provide a cable? What length? (Edit: I just read that Denon supplies a 39" RCA cable.) Does Denon also include adequate instructions as to how this cable's length may be longer only if the built-in equalizer is used?
View attachment 56724
If it isn't factored into the TT's built-in phono pre-amp, why would you expect it to be different with his AVR's phono pre-amp, or an external one?
The problem is complex. Every cartridge requires a different loading capacitance. The capacitance of the cables is a function of the length of cable a build. This issue is a major reason why results vary. SME use low capacitance cables and suggest soldering a cap to the terminals on the base of the arm to get the correct capacitance. The Quad 44 preamp, has dip switches to optimize loading capacitance.

I would doubt that a turntable RIAA preamp would have a loading capacitance, but I suppose it might, but how would the designer know what to choose. It so happens that the standard cable length of a TT has a capacitance that gets it in the ball park most often by pure luck.

However, if you have a cartridge such as the esteemed Shure V15 xmr, it requires a lower loading capacitance than the average. That is why many say the cartridge is dull. It is not if you load it properly. This was the reason that SME for its series III arms made the capacitance of the lead ultra low.

So it is likely that a turntable preamp presents an unusually low capacitance. Because of impedance issues the capacitance of the leads from the TT preamp to the amp or receiver will not change the issue.

This is an important issue understood by very few TT users these days.
 
O

OHMisback

Audioholic
Good information..

Few of the newer carts that I use need loading. I run a Silversmith Carman II MI. SME II, III, IV, 9 and 12" Arms. Ortofon Black and Bronze are good MM carts. I use them on Jelco 750 and SME I and IIs with non mag platters.

I can't use a Sure V15 XX on my magnetic platters like a Thoren TD124 I, I have to do a modification and raise the tonearm if I use a semi-fix. Series II or Russcos aren't magnetic.

I picked up my VTAs for around 175-200.00 each.. Usually that fixes most SQ issues

I haven't loaded a MM or MI cart for 10 years, I've had a few re-tipped. I keep a close eye on any RCA or XLR hooked to any part of a TT setup. The RCA cable from the tone arm can ruin a great sounding system. Low output carts even more so.

I have a 3020 Thoren that is converted to XLR/48 that was a big improvement as far as colorless cables. Very neutral, dead quiet and good pro cables work just fine. Length isn't so critical either. Under 10 meters I think.. LOL Pretty long..

I use a variant of the V15 II on most of my Russcos with Woodie Arms. Both were made 50 miles from me in Elk Grove for over 40+ years. I usually keep a cool dozen or so around for builds.. Russco, Sparta, or QRK. They have gear shifters, I love um.. I add 4lb of silicone dampening to the platters. 21 pounds total.

All that to say you need a good cable. :) and if TT are your thing get a great preamp. I started with Mac and EAR 50+ years ago. Herron and Decware are great values for the money if you want to step up. You can use a RtR with the Decware, it's set up if you order it that way.. Nuggets..

The wife is spinning 78 monos as I type. I'm using a modded Puffin that works very well for that application.

Time to fix the chicken coop.
 
TLS Guy

TLS Guy

Seriously, I have no life.
Good information..

Few of the newer carts that I use need loading. I run a Silversmith Carman II MI. SME II, III, IV, 9 and 12" Arms. Ortofon Black and Bronze are good MM carts. I use them on Jelco 750 and SME I and IIs with non mag platters.

I can't use a Sure V15 XX on my magnetic platters like a Thoren TD124 I, I have to do a modification and raise the tonearm if I use a semi-fix. Series II or Russcos aren't magnetic.

I picked up my VTAs for around 175-200.00 each.. Usually that fixes most SQ issues

I haven't loaded a MM or MI cart for 10 years, I've had a few re-tipped. I keep a close eye on any RCA or XLR hooked to any part of a TT setup. The RCA cable from the tone arm can ruin a great sounding system. Low output carts even more so.

I have a 3020 Thoren that is converted to XLR/48 that was a big improvement as far as colorless cables. Very neutral, dead quiet and good pro cables work just fine. Length isn't so critical either. Under 10 meters I think.. LOL Pretty long..

I use a variant of the V15 II on most of my Russcos with Woodie Arms. Both were made 50 miles from me in Elk Grove for over 40+ years. I usually keep a cool dozen or so around for builds.. Russco, Sparta, or QRK. They have gear shifters, I love um.. I add 4lb of silicone dampening to the platters. 21 pounds total.

All that to say you need a good cable. :) and if TT are your thing get a great preamp. I started with Mac and EAR 50+ years ago. Herron and Decware are great values for the money if you want to step up. You can use a RtR with the Decware, it's set up if you order it that way.. Nuggets..

The wife is spinning 78 monos as I type. I'm using a modded Puffin that works very well for that application.

Time to fix the chicken coop.
Well, we must be the only ones spinning 78 shellac discs.

This is my studio turntable case.





Left to right:- Garrard 301 with Decca FFSS H4E LP head and MK 11 78 head connected to Quad 22 tube preamp from 1966, recently restored.

Thorens TD 150 I bought in 1965 with SME series III arm with silicone dashpot damper and Shure V15 xmr, connected to Quad 44 preamp, Garrard 301 with SME series II arm with silicone dash pot damper, Shure V 15 xmr, connected to Quad 33 preamp.

Playing LP with Decca FFSS H4E on Decca pro arm.



Playing 78 rpm disc. You can also see a rare early Auriol lift I restored.



Now, the Quad 22 has combination buttons that allow for the correct playback Eq of just about any 78 disc produced prior to 1954.



This part of the "museum" also has a stand alone Dolby B encoder/decoder, and a dbx II encoder/decoder for tape, and a dbx II LP decoder. I do have a dozen or so, dbx II encoded discs.

Lastly, my family room system has a Thorens TD 125 Mk II with SME series III with silicone damper and Shure V15 xmr. I bought the Thorens for a song on eBay not working and restored it. That made a really nice turntable.

 
O

OHMisback

Audioholic
Wow, what a wonderful set up. I like the whole thing.. LOL I have projects everywhere, while a remodel is going on. The Covid Nightmare remodel is now in its 2nd year. I didn't get Covid, But I had a heck of a bout with a blood clot. 8 month from fit as a fiddle to can't breath so good. I'm gettin' better but sure slowed me down.

You're a Garrard Guy? I have a 401 50 hz here. I've had it 25 years.

401 and 301s when they are right people can say what they like, there is something special about both when they are set up.

The 78s are the wife for the most part, her Dads. 300+ in books. He was a Zoot suiter of sorts. The music reflects that, lots of jazz, salsa, south American, Island and Big Band music.

I'm more of a 45, 33 guy. RtR are Otari 5050 II and a Studer A810.

You ever mess with Russco, Sparta, or QRK?

I'm a Thoren and Russco die hard fan when I'm in the vinyl mood. 121,124 I & II. 3020.
SME is just hard not to like. :)

I'm pretty sure I have 6 or 8 TD160 and 165s

Russcos are just fun.

It won't let me upload a pic of a Russco I been working on for a guy. I have to figure that out. hum!

I used 1" oak stair flats for the plinths
The top swaps to fit most of the TT. Lynn, Garrard, Thoren or Russcos Broadcast TT
The stair flats are harder than heck. I'm taking them to a high gloss black automotive finish.
4th one I need to hire a motivated kid. LOL

I'm typing and just though, my arm is resting on a TD124 plinth with a 124 I. It has a Windsong top and cork dampener/Decware preamp. It's been setting there 6 months waiting on a 9" SME. The Tonearm was part of trade and the guy is really dragging his feet.

I'll figure out the pics.

I'm lazy I like streaming, CDs, I use a server. I'm not giving up the valve preamps or power amps in the winter though. Summer maybe the power amps..

Thanks for sharing..
 
highfigh

highfigh

Audioholic Slumlord
The problem is complex. Every cartridge requires a different loading capacitance. The capacitance of the cables is a function of the length of cable a build. This issue is a major reason why results vary. SME use low capacitance cables and suggest soldering a cap to the terminals on the base of the arm to get the correct capacitance. The Quad 44 preamp, has dip switches to optimize loading capacitance.

I would doubt that a turntable RIAA preamp would have a loading capacitance, but I suppose it might, but how would the designer know what to choose. It so happens that the standard cable length of a TT has a capacitance that gets it in the ball park most often by pure luck.

However, if you have a cartridge such as the esteemed Shure V15 xmr, it requires a lower loading capacitance than the average. That is why many say the cartridge is dull. It is not if you load it properly. This was the reason that SME for its series III arms made the capacitance of the lead ultra low.

So it is likely that a turntable preamp presents an unusually low capacitance. Because of impedance issues the capacitance of the leads from the TT preamp to the amp or receiver will not change the issue.

This is an important issue understood by very few TT users these days.
If Shure knew the capacitance needed to be lower, why didn't they change the cartridge to suit the majority of preamps? Trying to hit the jackpot is a PITA.

I always thought Shure cartridges sounded dull, as you wrote- that was with many brands of receivers, preamps and integrated amps which, generally didn't have much, if any, settings for capacitance or impedance. Sounds like Shure may have been digging in their heels. That said, I think that most Asian turntables had cheap tonearm wires that caused this. With the extremely high number sold, I would think Shure would want to be able to sell more and get a bigger piece of the pie.

Are the thick, black platters original to the turntables?
 
TLS Guy

TLS Guy

Seriously, I have no life.
If Shure knew the capacitance needed to be lower, why didn't they change the cartridge to suit the majority of preamps? Trying to hit the jackpot is a PITA.

I always thought Shure cartridges sounded dull, as you wrote- that was with many brands of receivers, preamps and integrated amps which, generally didn't have much, if any, settings for capacitance or impedance. Sounds like Shure may have been digging in their heels. That said, I think that most Asian turntables had cheap tonearm wires that caused this. With the extremely high number sold, I would think Shure would want to be able to sell more and get a bigger piece of the pie.

Are the thick, black platters original to the turntables?
I do not know the answer for sure, but I suspect it had to do with the design of the cartridge. The output of the V 15 series was a little below the norm for MM cartridges.
The moving mass of the V 15 xmr is very low, so I suspect all this is related to the design of the motor system. It could be that Shure agreed with SME and Peter Walker of Quad. Both were on record as advising turntables have as low a capacitance as possible, as you can add capacitance but not subtract it. The SME series III was designed specifically around the Shure V15 series, especially the xmr. The cartridge damper and the SME damper were designed to be synergistic. Back then the owners of these companies were also close friends. So it would be obvious to Peter Walker to design the Quad 44 to have adjustable PU loading capacitance to save having to solder caps at the base of the arm.

The UK in those days was a huge market for Hi-Fi equipment and especially for playing LPS. Also British UK gear had a big export market, especially to continental Europe and Canada. When I first went to Manitoba, Winnipeg was flush with Garrard, Quad SME and UK speakers.

All I can tell you is that when you use an SME arm with a Shure V15 xmr and Quad 44 pre amp, LP reproduction is absolutely superb.
 
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