Tuesday, July 14, 2015

Madison Area Summer Concert Highlights



Just wanted to take a moment and talk about some local venues in the Madison area. 

This time of the year were fortunate enough to have a plethora of outdoor  music venues to explore. One thing Madison does well every summer is music, over the last three or fours years the available shows has been outstanding and comparable to much larger metropolitan areas. 

A few spots are highlighted below including paid and free events. Id also like to notate Maximum Ink,  the only source for "homegrown" music expose, has an excellent section in the back outlining local/tri county and festival music events. 


Maximum Ink "A Home Grown Music Magazine Since 1996"


WUD Music Presents (Wisconsin Union Directorate Music Committee) Free
Starting Every Thursday into Saturday evenings typically around 5PM they host a series of free concerts at the Rathskeller/Memorial Union Terrace and a few at The Sett. The Rathskeller also host easy going sessions Fridays 5-7PM. Check their Facebook and WUD links for updated listings.

I recommend showing up a little early if you want a table and chairs, otherwise their is plenty of side and lake front seating available. Local and afar Beers and icecream/food options are available in and out of the Memorial Union. This is a personal favorite, I caught the Isthmus Jazz Fest here with Susan Hoffer, the Sangria kicks ass too.



Live on King Street (Majestic and Local Sponsors) FREE
Live on King Street is a series of concerts hosted on King Street in downtown Madison starting June 26th and running through September 18th in the cast of the Capitol building. This is its 5th year hosting and growing bigger and better each year.  I am incredibly excited to catch Benjamin Booker on September 18th. Remember their are at least 3 parking garages down there and the concerts are still FREE!  I recommend a Beer at Pauls or Coffee at Michelangelo's prior :)


Sunset Music Series (East Side Club) $
The East Side has hosted an impressive line up already this summer and continues the tradition with an affordable lake side outdoor mashup. Starting at 5PM most events with music at 6PM, for most children and teens shows are free with nominal 6$ tickets for adults. Ample parking for the most part and they welcome bringing your own chairs or paddle up to the dock! Plenty of food and beverage options available for cart vendors as well. 


Olbrich Gardens Summer Concert Series $
This is a relatively new series. Hosted at the world famous Olbrich Gardens on the West side. The grounds are a beautiful spot for concerts, arrive early to walk the paths and grab onsite parking. The offering is wide swatch from Jazz to Honky-Tonk at 7pm July 14th, 21st and 28th remaining. $1 minimum suggested donations and don't forget, bring a picnic and chairs or a blanket!




Wednesday, June 3, 2015

Altec Lansing 874A Segovia Speakers

Altec Lansing 874A Segovia's



We've got something real special here the last few weeks, a full original pair of Altec Lansing 874A Segovia's!

One thing real neat about the Segovia 874A is the 12" woofer was used exclusively in the Segovia, the magnet is just massive with an impressive extruded type basket design.  They operate in the 4 ohm range and have some decent cabinet weight to them. Inside you should find the original insulation :)



The crossover lo/hi pass networks consists of 4 core inductors, 2 rheostats and 2 6uf, 1 30uf and 1 100uf capacitors. An issue when recapping XO's especially when one uses polypropylenes exclusively is size, The customer opted for Dayton PP's in this case. 100uf caps are bigger than your fist. Although a little fore-thought in spacing like below and you'll see they fit quite nicely. Tie them up with some zips and your good to go. 

BEFORE


AFTER




Its important to add a new layer of gasket I think, especially if they tack glue the drivers. Check internal soldering connections and restful with some acousa-stuff if desired. Short of wishing these had the originals grills on them, Im having a hard time giving them up and back home, what an impressive set of 3-ways, truly!


Tuesday, June 2, 2015

Stereo.de highLight: Yamaha.De A-S1100 Verstärkers

Stereo.de highLight: Yamaha.De A-S1100 Verstärkers



I wanted to highlight Stereo.de article on the upcoming Yamaha A-S1100 Single-Ended (SE) Verstärkers.

We've been seeing a fairly big trend with older more etabliert
 manufacturers releasing throw-back styles. Last Week we took a look at the re-release of the proprietary Thorens suspension plattenspielers




Some neat caveats to note is the heavy stock electronically controlled attenuator und the use of a slightly better standard audio grade Nichicon FW lytics employed throughout the device along with the ECW panasonics which in my opinion is a vastly improved polypropylene film. Yamaha went with some custom canned Nippon filters for a total of 72,000 microfarads of smothering :) The absolute symmetric drive stage utilizes a compliment of MOSFET output devices in the singe-ended topography that should delivery that high biased/class A type of operation und a impressive reported 0.07% THD, yamaha had the fore-thought here to employ a discrete balanced MC/MM phono stage as well.



As discussed in Stereo.de one can see dual arranged 5-way plated output posts and robust "Tiffany" styled RCA inputs, same with the MM/MC inputs…impressive when you match it with the Cherry wood panel and piano black options. Available next month over the pond for € 1,699.






Saturday, May 30, 2015

Dual 510 Plattenspieler

Dual 510 Plattenspieler



Here we've got a German Dual 510 Plattenspieler. This came in with one channel out and for some repair from a previous "shop"

Whats nice about a lot of the Dual TT's is its fairly straight forward replacing interconnects. I prefer a end soldered connection. Custom length double shielded+RF RCA cables with strain reliefs were used, very similar to a co-axial type construction, I just love these cables, I use them almost exclusively besides the audio-quest interconnects now, ie long grain alloy ;)

you can read a lot of positives on the 510 series, the heavier mass platter and standard medium weight arm allows for fairly universal use, adapting cartridge bodies is also much easier requiring only some TK24 surmount vs than say a 506 series where a adapter is required. Like the 506 it uses a very nice, reliable 8-pole AC motor  I do want to note belts are readily available from many reputable resellers, both timing too. 




Its been a while since I played my "In the court of the Crimson King" album, but I have to say, love it on the 510! 


Friday, May 29, 2015

Sansui AU-717 Integrated Amplifier

Sansui AU-717 Integrated Amplifier




So here we've got a incredibly clean and pristine AU-717 integrated amp. Theres quite a few thing I like about the AU-717. The layout is very clean, they used proper shielding over all AF sections that we like to see, the shielding itself is attractive ,matching the clean black gloss finish elsewhere. The PCB locations and mounting make for some fairly quick work, especially when pulling the driver sections. I should note to properly pull the protection/PS one needs to pull the dual power transformers.  Also note, check your hex locations on the knobs first, on the 717 it really is a bitch.


Power Supply/Protection F-2663 PCB
Per my usual treatment I went with high temp, long life Panasonic FR/FCs strictly for this stage along with a pair of Nichicon high temp Bi-Polars (note some SM state 100/should be 220uf). The FR/FC series  delivers exactly what you want in a power supply, reliability.  Another addition is the installation of a new Omron relay, went with the 4PDT  MY-4 variant with the low noise action. 

Now as with most Sansui of this age and period we have some serious glue issues to attend to, the glue used is notoriously bad, it oxidizes to a degree and foreign particles create new tracing, as the glue sits on the component leads its causes oxidation and eats away at many resistors.  I recommend replacing any component that came into major contact with it and deep cleaning the PCB.  Another issue to note with the Sansui's are the fuse-able resistors. These absolutely need to go, when they fail they really fail and short. I recommend flame-proof MOX here. 

BEFORE


AFTER


Along with the glue, you will encounter several coated diodes as well, the 1S2473 had a great modern drop in available the 1N4148 and the larger diodes consists of ultra fast UF4003/02. 

Driver Stages F-2721/2722
For the lyrics on the driver stages I used audio grade Nichicon KW and Elna Silmic II capacitors. Again this board has the notorious glue on it, make sure ALL of it is remove and address and questionable resistors that were coated.  This particular model did not, but some may have fuse-ables at R23/25/26/16 locations, again I recommend flameproof MOX. 



The Au717 uses an interesting 1st stage topography along with a field-effect transistor   FET (2SK97) differential package, and quasi complimentary pairs at TR01/02 & Tr03/04. It is recommend to update the TR01/02 and Tr03/04 as was performed in this unit with ZTX694B and 992's BJT's.  On a last note I like to replace  biasing/offset potentiometers, IF, their not the old big fat white ones (those are great) the Au717 uses a series of two pots (100/2.2K) to dial in the Offset and one 1K for the Bias, right angle bourns were used here along with the fore-thought too add test points, too bad we dont see insight like that often. 

Pre-Tone Control  PCB F-2720
One thing I really liked about working on the AU717, especially in this stage is the molex type connections. It took just a few minutes to pull this section along with the huge enclosed stepped attenuator and F2666/F2665 assemblies for cleaning.  All the lyrics here were replaced again with audio grade Elna Silmic II's. One important thing to note is the AU717 used quite a few VD1212 type varistor diodes. These should all be removed and replaced with something a little more reliable and new, two 1N4148 in series (cathode to anode) work excellent.  Also, note we have 4X 82.5 ohm fuse-ables that need to be replaced with MOX or equivalents. This is a great time as I mentioned to pull the F2666/2665 assemblies to clean the controls, and tap the large enclosed attenuator to clean and lubricate. 


F2666/2665


EQ PCB F-2723
The EQ is fairly straightforward to work on, one can pull the extended shaft controls and simply pull the molex type connectors again ( :) ) All the lyrics were replaced with a low impedance , high reliability Nichicon PW and audio grade Elna Silmic II's here, the original C1/2 films were replaced with a better polypropylene WIMA film capacitor of the same value (250V). Again we see the VD1212 in X4 four position on this board D01-04 that need to be updated along with X4 four 82.5 ohm fuse-ables to replace. 



The rear panel F-2670 PCB has two lyrics I replaced with Nichicon PWs again, all the filter caps were replaced with X4 four 15Kuf 63Vdc Panasonic THA's, sadly these are nearing their run, it will be hard to find such a good filter cap replacement. 



Im very impressed with the AU717, I do wish the stepped attenuator had a vent, but that can be made, and as with most Kenwoods or Sansui's utilizing dual power supplies you usually end up pulling the Pformers out of the way. Still what a damn nice looking integrated, its is incredibly clean sounding I thought with just a touch of some lower end warmth. Quite impressed. 



Thursday, May 14, 2015

Kenwood C2 Pre-Amplifier Upgrade

Kenwood C2 Pre-Amplifier 





Here we've got a nice Kenwood C2 pre-amplifier. The unit came in for an overall recap and OPAMP upgrade. Leestereo of Audiokarma was very helpful with additional OPAMP information from his Kenwood C1 rebuild, big thanks to him and his work, truly top notch. 


open-booked main PCB assembly



Each stage has its own power supply, where as the electrolytic were replaced with high temp long Panasonic FR/FC capacitors, I prefer this application vs a audio grade. In a power supply were looking for an extremely reliable capacitor, the Panasonic FR/FC series deliveries just that.



 Note that the phono/tone/flat amp stages feed a 18.6-18.5Vdc rail to each OPAMP quadrant. the rated parameters of the NJM4580 and NJM2068 OPAMPs are 2-18Vdc.  For continued longevity of the OPAMPS D13/14/11/12 should be replaced with a 16-17Vdc zener to drop that operating 18.5-6vdc rail voltage. 




The following OPAMPS were upgraded along with new gold contact 8 pin DIP sockets for future rolling;
Phono - NJM2068DD
EQ stage - NJM4580DD
Tone Control - NJM4580DD
Filter stage - NJM4580DD



For all other electrolytic Elna Silmic or Bi-Polar MUSE ES were utilized, all low value lyrics were replaced with a polypropylene ECW Panasonic film capacitor.





I have to say, pairing this C2 with a Nikko 440 Alpha amplifier is quite impressive. There was a notable difference between the the original 2041DD JRC OPAMP and the NJM2068DD OPAMP. Impressed…. 


Wednesday, May 13, 2015

Bedini 25/25 Class A Power Amplifier

Bedini 25/25 Class A Power Amplifier



I wanted to share a little bit about this Bedini 25/25 Class A power amplifier. Rated at a mere 25W/CH it still has an impressive THD rating albeit fairly low dampening rating. I do want to note, apparently this is a very similar design to the 100/100 without updated 93/94 output devices.



This particular came in with some serious distortion issues, you could literally watch the wave form table-top with my Tektronix 2215 scope. Some previous work had been performed on the unit so unfortunately the quality fiberglass PCB had ignorant tracing issues. As well a axial general electrolytic was replaced with a trimmed audio grade Nichicon FG. I've noted across most major brands of the last few decades that axial tend to perform poorly compared to a radial and usually exhibit some form of excessive wear. In most cases the foot print only allows for a axial as you don't want much lead spacing exposed, but in this case it work perfectly.  Another update was to the complimentary differential pairs, vs a standard a/ab operation where we see a set of differential pairs, complimentary pairs are typically utilized in Class A operation due to the ON-ON type operation of the circuit. Standard KSC1845/KSA992s are damn near a perfect replacement, watch the pinout VS the original EBC.



Their is very little information available online, and the customer was incredibly useful in tracking done technical data, one leg that had to be worked out was a biasing issue.The threshold for the driver stage  is an impressive 550mV+ then you can achieve draw across the emitter resistor sets. Some models may not have a 2K potentiometer installed apparently. 




After figuring the Biasing issue and new components the floor was dropped considerably, audible distortion eliminated and a nice little amp was left.