Harman Kardon Citation 17 Upgrades

[AmCan]

This is my first thread and first DIY project. I bought a Harman Kardon 17/19 Combo for $500 and now I am going to completely upgrade the capacitors in the 17. In 1978 the Harman Kardon 17/19 combo was when Lee Kuby headed HK's CITATION Line and was working with Matti Ottala on improving intermodulated distortion. During the 1970’s Harman Kardon rivaled sales of McIntosh as some of the most expensive audio gear of its day.

Step One: Power Board. I am using Elna Silmic IIs for the higher Electrolytics and Mundorf ZNs for the perfect value match swap of .1uf. I will then be using Vishay 1837 metal film caps to stabilize the the power supply on the entire board.

Parts List
2 x 1000uF 50V Main Caps ***Note*** This is changed later to 2 x 2200uF 63V Mundorf M-Lytic
8 x 10uF 35V
1 x 2.2uF 50V
1 x 220uF 16V
2 x .1uF Vishay 1837 bypass caps

 

[dshoaf]

Have done the same thing. Also, consider swapping the 3-terminal regulators, too. The technology has come a long way with them, too.

Otherwise, make sure the new operating voltages are in spec then move on to the line stages.

Are those pre's easy to work on?

Cheers,

David

 

[AmCan]

Have done the same thing. Also, consider swapping the 3-terminal regulators, too. The technology has come a long way with them, too.

Otherwise, make sure the new operating voltages are in spec then move on to the line stages.

Are those pre's easy to work on?

Cheers,

David

Thanks for the suggestion. I was under the impression that if there is no damage to the unit, i.e. burnt out capacitors, that the resistors and regulators should be o.k. ? I have the tech repair manual and it talks about adjustments to the phono preamp board and E.Q. boards but not about measuring the operating voltages. The operating voltage for this unit is up to 14 volts RMS into 2200 ohms or greater. Where is the best place to measure the voltage? I assume that I can do it with my multimeter?

Up until now I thought this was going to be easy to work on but I am not prepared to make adjustments because I do not have any testing equipment short of a multimeter. Removing the boards are very easy to access and remove and replacing the capacitors are straight forward. That part I understand.

 

[dshoaf]

3-terminal regulators had just hit the market in the mid-70s and were quite popular due to their ability to reduce parts count and for their performance specs. If you don't have a scope to measure the AC output from them, I'd suggest they can be on your 'second pass' of upgrades to consider.

The key, though, is to be sure that the different regulated voltages that are developed on the power supply board are, in fact, within spec. To do this, turn the preamp over and take off the bottom cover. There, you'll find each and every pin of the sockets labeled including the voltage distributions. I'd suggest you measure all those pins and trace them in the wiring diagram in the service manual.

As for the adjustments, I'd suggest not to mess with them. The one for the phono preamp would require a distortion meter plus a related low-distortion signal generator. I don't tend to keep that stuff around due to cost and the few times it is really needed. Best to just leave the adjustments alone. If you'd like, though, get some nail polish and drop a blob on the adjustments to keep them from being bumped if you plan to be inside the unit a lot.

Cheers,

David

 

[AmCan]

3-terminal regulators had just hit the market in the mid-70s and were quite popular due to their ability to reduce parts count and for their performance specs. If you don't have a scope to measure the AC output from them, I'd suggest they can be on your 'second pass' of upgrades to consider.

The key, though, is to be sure that the different regulated voltages that are developed on the power supply board are, in fact, within spec. To do this, turn the preamp over and take off the bottom cover. There, you'll find each and every pin of the sockets labeled including the voltage distributions. I'd suggest you measure all those pins and trace them in the wiring diagram in the service manual.

As for the adjustments, I'd suggest not to mess with them. The one for the phono preamp would require a distortion meter plus a related low-distortion signal generator. I don't tend to keep that stuff around due to cost and the few times it is really needed. Best to just leave the adjustments alone. If you'd like, though, get some nail polish and drop a blob on the adjustments to keep them from being bumped if you plan to be inside the unit a lot.

Cheers,

David

Thanks David. I'll start by doing as you have suggested. Hopefully nothing will be off.

 

[ficklecycler]

Interesting project here. Keep us updated on your progress. I've got a Citation 17S that likely needs the same treatment.

 

[AmCan]

Interesting project here. Keep us updated on your progress. I've got a Citation 17S that likely needs the same treatment.

Absolutely I will keep posting pictures.

Last night I went to measure the voltages and accidently put the probe to the AC in pin and blew the slow blow fuse. Of course it was only a 2 AMP fuse, which everything else I have has 3 A fuses in it so I am off to Radio Shack to get some new ones today. I have completed the Output Board and will post those later. I don't expect there to be problems with the voltages because it is working fine (better than new actually ) but I will heed David's advice and measure. This is what I was hoping to get out of doing it myself and posting - learning something new from other members.

 

[AmCan]

Voltage Readings

O.k. I replaced the fuse and managed to read all the voltage terminals. Most of the reading where within a 1/2 a volt like this positive voltage reading of 24.4 volts on a 24 volt pin. One of the negative readings seen here however is -15.18 on a negative 14 volt pin. What are acceptable ranges for these type of readings? I don't recall any other reading being more than a volt off.

 

[AmCan]

Output Board

I upgraded the output board with the following capacitors:

4 x .1 uF 630V Mundorf ZN
2 x .22 uF 1200V Mundorf Supreme
2 x .001uF Vishay 1837 (metal film bypass for M Cap)
2 x 220uF 35V Elna ***Note*** This is changed later to 2 X 330uF 35V Nichicon KZ Muse
2 x 220uF 16V
2 x 10uF 35V
2 x 2.2uF 100V
2 x 47pF 500V Silver Mica
2 x 7pF 500V

I did not arrive at this final arrangement in a straight line. I originally selected all Mundorf Zns for the film caps because of their affordability and smaller size plus high loss factor. Because 2 of the film caps on this board were toasty looking I assumed they were .1uF when actually they were .22uF. My mistake gave me me an opportunity to correct it by moving up a notch to the Supremes and try bypassing them with the Vishay metal films, which has been discussed before in capacitor reviews. I had an opportunity to listen to all of these capacitors in a stage wise fashion. Before bypassing the M Cap Supremes I listened to them for the weekend. The ZNs have a very honest, neutral sound to them with a nice size sound stage and are VERY detailed. They are more detailed than the M Cap Supremes in my opinion. In fact when I put the Supremes in I thought I made a big mistake not sticking with my original plan of using all ZNs for the films. The Supremes have a very tube like quality to them and I don't mean warm as much as grainy. The soundstage is vast and open more so than the ZNs but there is a loss of detail from the ZNs. The solution is to bypass the Supremes with a little Vishay metal film and WOW :thmbsp: does it make a difference. The vastness of the soundstage is retained but the clarity and detail of the ZNs are restored. Professional reviewers equate this to almost as good as the Silver/Oils but certainly the best bargain to be had. The silver/Oils are 3x the price.

 

[thefragger]

 

[sfox52]

I'm waiting till you get to the amp. I've had a stock 19 for a year or so & I can't decide whether to recap it or take it to a local AK get-together to move it along. If I do sell it I'll point out this thread to the buyer.

 

[AmCan]

I'm waiting till you get to the amp. I've had a stock 19 for a year or so & I can't decide wheter to recap it or take it to a local AK get-together to move it along. If I do sell it I'll point out this thread to the buyer.

Thanks. I am going to get to the amp as soon as I can sneak another $200 parts bill past my wife. The 19 does have some upgrades in it already. When I bought it the owner said only the main power caps had been replaced with Mallory 10,000uF. However, when I looked at the driver boards they have Baby Blue Rubycons on them that don't look stock. They appear to be from around 1992 based on the label design (I searched for images). The owner of this combo had them sitting on the shelf as he was a collector but used his 16/17s more. Thats why I started with the 17, which was completely outdated. I did update one coupling cap in the 19 before I started the 17, which made a minor almost unnoticeable improvement on its own but I know that there is potential to be released. I don't like the way those Mallory Big Can are attached only with one screw.

 

[AmCan]

Phono Board Advice Needed

Hey, does anyone have any suggestions for these huge polyester film caps? They are 8200pF 63V 2.5%. I have 2 extra .1uF Mundorf ZNs and I want to use them there if that is an acceptable jump? Plus, I am not really sure what the advantages might be one way or the other. So far I have not increased capacitance anywhere because I am not sure what the rule is on when or how much larger one can go? Any opinion would be helpful. I have attached the circuit diagram.

 

[ficklecycler]

How are things coming along with the project?

 

[AmCan]

Voltage Tolerances

O.k. I replaced the fuse and managed to read all the voltage terminals. Most of the reading where within a 1/2 a volt like this positive voltage reading of 24.4 volts on a 24 volt pin. One of the negative readings seen here however is -15.18 on a negative 14 volt pin. What are acceptable ranges for these type of readings? I don't recall any other reading being more than a volt off.

I was at the Toronto Audio and Video Exhibition and ran into Brian Smith, proprietor of Audio Note Kits, at their booth. Man would I love to build one of their DAC kits. They looked like the place to go up from my Grant Fidelity Tube DAC. Anyway, Brian was nice enough to answer this question for me regarding tolerances for the -/+ voltage rails. Brian said that anything within 10% was fine. The idea is that there simply needs to be potential for current flow. Looks like I will have to save up the money for one of those kits but what I liked was their willingness to give support. Brian was a nice guy, great looking kits, check them out.

 

[AmCan]

How are things coming along with the project?

Things are moving more slowly now that I am almost done with the phono board but I will post on my progress. I am spending most of my time looking at what caps to get to go into the 19 before placing an order for the remaining caps that I need for the phono board.

 

[Sir.Byrd]

Have you considered going up in capacitance for the main filter caps?

 

[AmCan]

Thanks to Parts Connexion.

Hey, does anyone have any suggestions for these huge polyester film caps? They are 8200pF 63V 2.5%. I have 2 extra .1uF Mundorf ZNs and I want to use them there if that is an acceptable jump? Plus, I am not really sure what the advantages might be one way or the other. So far I have not increased capacitance anywhere because I am not sure what the rule is on when or how much larger one can go? Any opinion would be helpful. I have attached the circuit diagram.

Since the answer to my question was not forth coming I contacted Parts Connexion for some technical support and they gave me a really great suggestion for the high value pF polyester caps. They recommended I go with the REL RTE - Polystyrene Film and Foil ( 2% - Radial Leads - Square Case - Epoxy Filled ). They come in the both the 3200 & 8200 pF that I need. Reviews of these caps say that they are a good upgrade choice and peg them as sounding detailed & sweet. I will have to wait awhile to find out as I don't plan on ordering them until I am ready to order the caps for my 19.

 

[AmCan]

Have you considered going up in capacitance for the main filter caps?

In the 19 or 17?

Since I am not adept at determining how to modify a circuit I decided to keep all the values the same, with the exception of increasing voltage rating where I could such as with the film caps. I wasn't sure how big I could go or what the rule of thumb is regarding going bigger. Especially where the coupling caps are concerned. Would increasing the value of a .1uf film cap to a .22uf film cap have a dramatic effect on response time (Inductance)? I am open to suggestions.

One thing about the 19 is that space is tight height wise with only about 80mm of space, which have eliminated the Mundorf Big Cans for me and I am very disappointed about that. The newer 10,000uf are 100mm in height. The only thing that will fit are the Nichicon Super Throughs Solder Lugs at 10,000uf 80V, which shouldn't be too shabby, right? The 15,000uF / 100V, KG Series, Gold Tune, 63x80mm, would fit. The circuit calls for 85V on 55 rails. What do you think?

 

[AmCan]

Phono Preamp Board

Well I finally have the phono preamp board done. At first I was usure what to do about the high value pF polyester film caps on this board. So I replaced everything but the 2400pF and 8200pf polyester caps and the board sounded choked. Upon the recommendation form Parts Connexion Technical service I then replaced them with REL RTE Polystyrene Film and Foil caps and the PCB came to LIFE! It was as if I added a gain stage to the phonostage. It was so obvious a gain I could not believe it. Because they were out of the 8200 I jumped up to a .01, which is not much of an increase. I also found some multicaps to replace a very low .0039uF film cap. They were relatively expensive but worth every penny. Here is the Board. I am going to make one more cap switch and then I will post the values. I am going to increase the capacitance of the 220uF Elna Silmic to 330uf KZ Muse. I did this with the output board with great success. I will post that later as well. In addition, I have picked up some larger Mundorf main power at the suggestion of Sir Bird. I haven't increased capacitance everywhere but I think it is warranted in a few key places.