Denon TU-800


John Boros
 

Hello everyone,

I’m in need of your sage advice.

My Denon TU-800 is a wonderful tuner, its strengths are its sensitivity, bass and holographic sound. Unlike my hot rod Sansui TU-9900, it is not transparent and/or smooth, but, rather, has a dry sound.

From experience, I know the benefits of recapping, but, I also know it can alter the character of the SQ and, so, I don’t want to get carried away with updates, am going to focus first on the audio section and, perhaps, the decoupling caps - if these are influential to the sound?

Here’s John’s list, which he was kind enough to share:

Audio 

Signal Path:

IC303 – BurrBrown OPA2134PA OpAmp

C331/332 – 2.2/250 Panasonic ECWF Metalized Polypropylene Film

            The schematic calls for a 4.7µf, OEM actually installed was a 0.47µf.  2.2µf gives a 2Hz -3db 

point using a 50K load at the pre.

R326/327/328/329/332/333 – Same value, I used PRPs but Dales probably just as good.

 

Decoupling

C330 – 120/16

C333 – 220/35




Unfortunately, the parts list, on Tic, seems to be incomplete, resistors R326 to 333 are not listed; can anyone help?


And, can anyone tell me what the original cap and resistor types are, poly and carbon comp, for example? I’m hoping that by using the original types, it will help retain its desirable sonic character. 


Lastly, any and all advice appreciated.


Thanks,


John


John Carpanini
 

Hi John,

  For the resistors what I was trying to indicate, apparently poorly, was to use the same value as OEM in 1% metal film, the originals are 5% carbon film.  The schematic is available over on the TIC for you to work from. A quick check indicates the following:
R326/327/328/329 - 3.3k
R332/333 -  560 Ohm

As for the caps, all the ones you've indicated are electrolytic caps, replace all the decouplers with the same but I recommend to use films for the audio signal path. specifically 331/332.  Films will provide a more Sansui like presentation IMHO. 

It would be great if you could confirm what the factory installed in the 331/332 locations.  Like I said in some of the ones I've had through here were not as indicated on the schematic.  Keep in mind that you have to fit in there whatever you select , which is why I chose the metalized films for that location.  The film & foil variant were too big to fit conveniently.

Regards
JohnC


John Boros
 

Excellent, John, 

Thank you! I will have a look at what’s in there before I decide and complete the order for parts.

John, the opamp, Brunson makes a discrete replacement; is this a good, or, a bad idea?

Thanks,

John

On Mar 8, 2020, at 4:24 PM, John Carpanini <jacarp@...> wrote:

Hi John,

  For the resistors what I was trying to indicate, apparently poorly, was to use the same value as OEM in 1% metal film, the originals are 5% carbon film.  The schematic is available over on the TIC for you to work from. A quick check indicates the following:
R326/327/328/329 - 3.3k
R332/333 -  560 Ohm

As for the caps, all the ones you've indicated are electrolytic caps, replace all the decouplers with the same but I recommend to use films for the audio signal path. specifically 331/332.  Films will provide a more Sansui like presentation IMHO. 

It would be great if you could confirm what the factory installed in the 331/332 locations.  Like I said in some of the ones I've had through here were not as indicated on the schematic.  Keep in mind that you have to fit in there whatever you select , which is why I chose the metalized films for that location.  The film & foil variant were too big to fit conveniently.

Regards
JohnC


John Boros
 

John,

I checked the schematic and can’t find the info (might be my eyesight); the resistors, what wattage are they?

And, if I’m trying to retain the character of the SQ, is there any harm in using 1% carbon film resistor replacements? What is the advantage of using metal film?

Thank you,

John

On Mar 8, 2020, at 4:24 PM, John Carpanini <jacarp@...> wrote:

Hi John,

  For the resistors what I was trying to indicate, apparently poorly, was to use the same value as OEM in 1% metal film, the originals are 5% carbon film.  The schematic is available over on the TIC for you to work from. A quick check indicates the following:
R326/327/328/329 - 3.3k
R332/333 -  560 Ohm

As for the caps, all the ones you've indicated are electrolytic caps, replace all the decouplers with the same but I recommend to use films for the audio signal path. specifically 331/332.  Films will provide a more Sansui like presentation IMHO. 

It would be great if you could confirm what the factory installed in the 331/332 locations.  Like I said in some of the ones I've had through here were not as indicated on the schematic.  Keep in mind that you have to fit in there whatever you select , which is why I chose the metalized films for that location.  The film & foil variant were too big to fit conveniently.

Regards
JohnC


Herb Ward
 

John and John,

Both Wima and Kemit make 50 or 63 volt MKP films which are small enough to fit neatly ( well for the most part anyways ) in place of the typical electrolytics. Film and foils might be better in some theoretical aspects, but do keep in mind that a modest modern mylar film cap can be orders of magnitude better than many electrolytic caps. ( and like Sears, there are good , better, and best MKP’s ) And at the risk of being flamed alive , the current COG or NPO MLCC caps may be a good alternative choice. ( up to 22uf ! ) Do keep in mind that a modern series 1 ceramic cap is a very different animal than the usual ceramics which are not appropriate for audio frequency signal path applications. The popularity of COG/NPO MLCC ceramic caps have really driven down the prices. NOS polystyrene are often ???, and the price of mica is way up there. With respect to your resistor question, 1% CF’s offer no benefit except in filters or tuned circuits IME.

HRW

On Sun, Mar 8, 2020 at 5:07 PM John Boros <jsjb@...> wrote:
John,

I checked the schematic and can’t find the info (might be my eyesight); the resistors, what wattage are they?

And, if I’m trying to retain the character of the SQ, is there any harm in using 1% carbon film resistor replacements? What is the advantage of using metal film?

Thank you,

John

On Mar 8, 2020, at 4:24 PM, John Carpanini <jacarp@...> wrote:

Hi John,

  For the resistors what I was trying to indicate, apparently poorly, was to use the same value as OEM in 1% metal film, the originals are 5% carbon film.  The schematic is available over on the TIC for you to work from. A quick check indicates the following:
R326/327/328/329 - 3.3k
R332/333 -  560 Ohm

As for the caps, all the ones you've indicated are electrolytic caps, replace all the decouplers with the same but I recommend to use films for the audio signal path. specifically 331/332.  Films will provide a more Sansui like presentation IMHO. 

It would be great if you could confirm what the factory installed in the 331/332 locations.  Like I said in some of the ones I've had through here were not as indicated on the schematic.  Keep in mind that you have to fit in there whatever you select , which is why I chose the metalized films for that location.  The film & foil variant were too big to fit conveniently.

Regards
JohnC


John Carpanini
 

Hi John,

 The Burson OpAmps are very nice, and the price reflects that.  Also keep in mind that you're dealing with a tuner, which by definition is of limited bandwidth, basically 15Hz to 15KHz.  The advantages of the Burson, Orange, and other discrtete OpAmps is generally heard at the frequency extremes that just don't exist in a tuner.

If you want to try something better than a 2134 try a OPA2604, it stays in Class A longer than the 2132/2134 but has a chance of oscillation in that circuit.

You have DQ10s, if I remember correctly, if you don't have some very good subs on them you won't hear the bottom end differences anyway.  Just my $0.02

Best Regards

JohnC


On 3/8/2020 4:47 PM, John Boros wrote:
Excellent, John, 

Thank you! I will have a look at what’s in there before I decide and complete the order for parts.

John, the opamp, Brunson makes a discrete replacement; is this a good, or, a bad idea?

Thanks,

John

On Mar 8, 2020, at 4:24 PM, John Carpanini <jacarp@...> wrote:

Hi John,

  For the resistors what I was trying to indicate, apparently poorly, was to use the same value as OEM in 1% metal film, the originals are 5% carbon film.  The schematic is available over on the TIC for you to work from. A quick check indicates the following:
R326/327/328/329 - 3.3k
R332/333 -  560 Ohm

As for the caps, all the ones you've indicated are electrolytic caps, replace all the decouplers with the same but I recommend to use films for the audio signal path. specifically 331/332.  Films will provide a more Sansui like presentation IMHO. 

It would be great if you could confirm what the factory installed in the 331/332 locations.  Like I said in some of the ones I've had through here were not as indicated on the schematic.  Keep in mind that you have to fit in there whatever you select , which is why I chose the metalized films for that location.  The film & foil variant were too big to fit conveniently.

Regards
JohnC


John Boros
 

Hello, John &

You have a good memory! Yes, I have a pair of DQ10’s, with an active sub.

Nevertheless , the opa2604 @ $4.95, has me convinced, given the Burnson starts @ $70! I will give this.a try & thank you!

John, I assume the resistors are 1/4 watt?

Thanks,

John

On Mar 8, 2020, at 8:04 PM, John Carpanini <jacarp@...> wrote:



Hi John,

 The Burson OpAmps are very nice, and the price reflects that.  Also keep in mind that you're dealing with a tuner, which by definition is of limited bandwidth, basically 15Hz to 15KHz.  The advantages of the Burson, Orange, and other discrtete OpAmps is generally heard at the frequency extremes that just don't exist in a tuner.

If you want to try something better than a 2134 try a OPA2604, it stays in Class A longer than the 2132/2134 but has a chance of oscillation in that circuit.

You have DQ10s, if I remember correctly, if you don't have some very good subs on them you won't hear the bottom end differences anyway.  Just my $0.02

Best Regards

JohnC


On 3/8/2020 4:47 PM, John Boros wrote:
Excellent, John, 

Thank you! I will have a look at what’s in there before I decide and complete the order for parts.

John, the opamp, Brunson makes a discrete replacement; is this a good, or, a bad idea?

Thanks,

John

On Mar 8, 2020, at 4:24 PM, John Carpanini <jacarp@...> wrote:

Hi John,

  For the resistors what I was trying to indicate, apparently poorly, was to use the same value as OEM in 1% metal film, the originals are 5% carbon film.  The schematic is available over on the TIC for you to work from. A quick check indicates the following:
R326/327/328/329 - 3.3k
R332/333 -  560 Ohm

As for the caps, all the ones you've indicated are electrolytic caps, replace all the decouplers with the same but I recommend to use films for the audio signal path. specifically 331/332.  Films will provide a more Sansui like presentation IMHO. 

It would be great if you could confirm what the factory installed in the 331/332 locations.  Like I said in some of the ones I've had through here were not as indicated on the schematic.  Keep in mind that you have to fit in there whatever you select , which is why I chose the metalized films for that location.  The film & foil variant were too big to fit conveniently.

Regards
JohnC


John Carpanini
 

Yes the OEMs are 1/4W, but, and there's always a but, I generally work with 1/2W parts as long as I have the room.

JohnC


John Boros
 

John,

You’ve been very helpful!

Thank you!

John

On Mar 8, 2020, at 8:53 PM, John Carpanini <jacarp@...> wrote:

Yes the OEMs are 1/4W, but, and there's always a but, I generally work with 1/2W parts as long as I have the room.

JohnC


rick.savas@...
 

Hi guys,

In my new designs I have been using Vishay MBB0207 & MBA0204, thin film, not much better imo @ 50ppm t/c, check them out, available at Mouser and Digi-Key

Cheers Rick

On Mar 8, 2020, at 8:53 PM, John Carpanini <jacarp@...> wrote:

Yes the OEMs are 1/4W, but, and there's always a but, I generally work with 1/2W parts as long as I have the room.

JohnC


Radu Bogdan Dicher
 

For resistor mods/upgrades/repair I highly recommend Vishay's CMF/RN (industrial/milspec) resistors. They are extremely rugged, low noise, and - relating to points just made - are spec'ed for two different power ratings depending on environmental temperature. For instance, RN55 series is 0.1W @ 125C and 0.25W @ 70C (which is still pretty high a temperature). They have series going to 3/4W, but I suspect in actual use they can withstand well above that. If you've never used one, examining one with own hands exudes unmatched quality. 

My go to resistor is the CMF55/RN55, which has never (unexpectedly!) failed me (even in - typically hot - tube applications). By that, I mean to put a fine point: when they need to go - for instance, if they are on K of a shorted tube - they go away cleanly. 
Radu. 

On Sun, Mar 8, 2020 at 5:56 PM John Boros <jsjb@...> wrote:
John,

You’ve been very helpful!

Thank you!

John

On Mar 8, 2020, at 8:53 PM, John Carpanini <jacarp@...> wrote:

Yes the OEMs are 1/4W, but, and there's always a but, I generally work with 1/2W parts as long as I have the room.

JohnC


John Carpanini
 

Hi Rick,
 yea those look to be pretty nice, will have to give them a try.  Do you know if they have steel leads or copper??

 And while I'm at it Radu's recommendation for the Vishay CMF/RN parts is right on.  I just call them Dales, the old original name.

Regards
JohnC


rick.savas@...
 

Hi John, from the data sheet
Vishay Beyschlag

 Plated steel termination caps are firmly pressed on the metallized rods. A special laser is used to achieve the target value by smoothly cutting a helical groove in the resistive layer without damaging the ceramics. Connecting wires of electrolytic copper plated with 100 % pure tin are welded to the termination caps. 

Another one I have been using for a long time going back to the MECL design days are SFR16s type

On Mar 9, 2020, at 2:33 AM, John Carpanini <jacarp@...> wrote:

Hi Rick,
 yea those look to be pretty nice, will have to give them a try.  Do you know if they have steel leads or copper??

 And while I'm at it Radu's recommendation for the Vishay CMF/RN parts is right on.  I just call them Dales, the old original name.

Regards
JohnC


John Boros
 

Rick, Randy & Herb,

Thank you for your recommendations, will have a go, will research all this. Today I hope to open up the ole Denon and confirm parts needed and place my order.

Parts connexion is near me and I noticed they sell Vishay z - foil resisters and having looked into them, they come very highly recommended. Are these the top of the food chain? By the descriptions I’ve read, they would seem so.

Thanks,

John

On Mar 9, 2020, at 7:25 AM, rick.savas@... wrote:

SFR16s


rick.savas@...
 

I have no experience with z-foil types, not sure if they make any sense in these applications, especially with the expense involved

On Mar 9, 2020, at 7:56 AM, John Boros <jsjb@...> wrote:

Rick, Randy & Herb,

Thank you for your recommendations, will have a go, will research all this. Today I hope to open up the ole Denon and confirm parts needed and place my order.

Parts connexion is near me and I noticed they sell Vishay z - foil resisters and having looked into them, they come very highly recommended. Are these the top of the food chain? By the descriptions I’ve read, they would seem so.

Thanks,

John

On Mar 9, 2020, at 7:25 AM, rick.savas@... wrote:

SFR16s


John Boros
 

Good morning, John &

in looking at the schematic, resistors R330 & R331 seem also to be in the signal path; should these not also be changed?

Thanks,

John 



---------- Original Message ----------
From: John Carpanini <jacarp@...>
Date: March 8, 2020 at 8:53 PM

Yes the OEMs are 1/4W, but, and there's always a but, I generally work with 1/2W parts as long as I have the room.

JohnC


 


John Boros
 

Hello again, John &

I pulled the cover of the TU-800 and indeed, C331/332 are .47uf

C330 is 47 uf, 10v and you're recommending an electrolytic (120/16)?

C333 is 100 uf, 16v and ……...………………………………    (220/35)?

For these two electrolytic replacements, there is a myriad of choices, Nichicon, Elna, Cornel, Mundor ... Bipolar, Z, K …. lol I'm not savvy enough to know what would be ideal and am guessing it's not very critical; but, can you recommend one?

I've researched the film caps and the Panasonics that you used come highly recommended. I've used a Kesmet ceramic cap in a power supply of my steamer, but, not sure how it could suit the situtation here?

Thank you, 

John 



---------- Original Message ----------
From: John Carpanini <jacarp@...>
Date: March 8, 2020 at 4:24 PM

Hi John,

  For the resistors what I was trying to indicate, apparently poorly, was to use the same value as OEM in 1% metal film, the originals are 5% carbon film.  The schematic is available over on the TIC for you to work from. A quick check indicates the following:
R326/327/328/329 - 3.3k
R332/333 -  560 Ohm

As for the caps, all the ones you've indicated are electrolytic caps, replace all the decouplers with the same but I recommend to use films for the audio signal path. specifically 331/332.  Films will provide a more Sansui like presentation IMHO. 

It would be great if you could confirm what the factory installed in the 331/332 locations.  Like I said in some of the ones I've had through here were not as indicated on the schematic.  Keep in mind that you have to fit in there whatever you select , which is why I chose the metalized films for that location.  The film & foil variant were too big to fit conveniently.

Regards
JohnC


 


John Carpanini
 

Hi John,
  Sure if you'd like to, they are in the feedback loop of the OpAmp.  A couple of metal films in there would be just fine, considering that the majority of the work is getting the board out and back into the chassis. why not?

JohnC


John Carpanini
 

John,
 With regards to any of the decoupling locations and the power supply use the following:

 

For all decoupling & Power Supply caps, use the following (Manufacturer/Series): Panasonic FR, FM, Nichicon HE, or Panasonic FC in that order, as available.

JohnC


Radu Bogdan Dicher
 

JohnC,
The reason you're putting FRs in front of FMs is longer service hours? ESR seems to match, not sure how size stacks up one on one. Also, they seem to retire FMs (haven't these come into the market relatively recently?... Or maybe I'm older than I like to admit). 

Just curious as to your thinking on this. 

Radu. 


On Mon, Mar 9, 2020, 10:09 AM John Carpanini <jacarp@...> wrote:
John,
 With regards to any of the decoupling locations and the power supply use the following:

 

For all decoupling & Power Supply caps, use the following (Manufacturer/Series): Panasonic FR, FM, Nichicon HE, or Panasonic FC in that order, as available.

JohnC