Marantz 1030 Integrated Amplifier

Marantz 1030 Integrated Amplifier

The Marantz Integrated Amplifiers happen to be one of my favorite 70's Marantz pieces. Being a big fan of the 2230 similar 1060 Integrated, I knew id love the like sound of the 1030 Integrated. Rated at a conservative 15 Watts a channel, the 1030 uses a very similar pre-amplifier topography again as the 1060. The phono stage features shielding I haven't seen yet on any 1060's either.

Power Supply;

The regulated 35V+/37V+ power supply is fairly straight forward on this model, replacing electrolytics with high temp, long life Panasonic FR/FC's. Several Carbon Composite resistors were replaced as well with MOX Flame-Proof, all glue was removed. 

The filter caps in these are positioned smack in front of the amplifier sections, which of course is a source of significant radiant heat. I like to come back, same with 22XX receivers who position these against driver sections, but I like to install a smaller foot print electrolytic here. This increases the overall area around the drive boards and decreases the subjected heat these caps experience. I increased the values  here past the 20% extreme at 4700 for 2200 and 6800 at 4700's microfarads. To finish up a new 7A EG1018 power switch and X1Y2 rated safety capacitor was installed.

Pre-Amplifier

Again, with such a close topography minus the 1st stage, to the bigger 1060 Integrated I want with a similar compilation. Using low impedance PW's and Elna Silmics and small values with WIMA film capacitors. the coupling stage original Mylars were replaced with a Polypropylene MPK Solen. 

Marantz 1030

Marantz 2230

Phono

The phono stage was similar to others, updating 2SC458 Bi-Polar Transistor pairs to KSC1845's and Elna Silmics/PW's. Its important to notate that C909/910 is an axial type electrolytic shunted with a 100ohm 1/4W resistor to ground. 

Driver Stages

One important update to perform on the the symmetric driver stage is the H715/716 Diodes (1N60) to a series of 1N4148 diodes for reliability and adding Bourns Precision 500/100K trimmer potentiometers. Differential Pairs to matched Hfe 1845's. The coupling C725/26 and 01/02 were upgraded with polypropylene Solens and WIMA MK film capacitors, Elna/PW's were used for electrolytics throughout. 

OUTPUTS

Several variations on output devices were tried and tested due to a repair required. original TO-66's are hard to come by, I recommend for a different option using MJE15032 NPN TO-220 type BJ-Transistors if necessary with some slight heatsink modifications and SilPads. 

Infinity Quantum 5 (Q5) Speakers XO Rebuild

Infinity Quantum 5 (Q5) Speakers

I wanted to come back to a pair of speakers we had in a few months ago.

This is a pair of Infinity Quantum 5's. These are beautiful speakers, with an interesting L-style metal pedestals thats factory and a neat elevated grill snap. These are rated at a nominal 4 ohm load with a driver range of 30-250Watts (38-32KHz +3dB)

One major thing I'd like to highlight on the Quantum series are the EMIT tweeters. Now I absolutely love how these sound, but I haven't come across such a delicate tweeter in my life. At this point in their lives many have started to delaminate the VC tracing from the diaphrams. Another issue with the EMITs are the solder pads for connections, many have developed bad solder joints and simply reflowing will get ya back to reading proper ohms. Thats not to say their bad, the electrostatic design and extreme Cobalt magnetics are nothing to scoff at. 

The lower frequency driver is a dual voice-coil Watkins driver, these are phenomenal drivers that were built like tanks.  The midrange driver is a poly type dome construction sweeping from 600 to 4KHz<.

The bug with these speakers is to pull the EMIT and test them, reflow if necessary and attack the cross-overs. They use two pretty well constructed standard can type electrolytics along with an array of film polypropylenes, three inductors, rheostat and phenolic potentiometer.  The can type electrolytics were replaced with two axial electrolytics in parallel to obtain the correct value, all the original films were replaced with a much higher quality Solen MK type polypropylene capacitor in a similar fashion. (XO Points of perception 600Hz,4kHz)

**one major notation I want to add is the fuse, do not use the original rated value, I highly recommend .5-.750mA fuse as really anything over and you can say good bye to those EMITs.

BEFORE

AFTER

With correct placement and proper drive these truly sound amazing before and after. They look just stellar with a proper cleaning and the heavily constructed metal pedestals. 

Pioneer SX-550 Receiver

Pioneer SX-550 Receiver

Here we've got a nice Pioneer SX-550 in for a restoration. The unit came in quite dirty from typical wear and tear and the faceplate, quite the build up on the plate and knobs. I was extremely happy with how clean the knobs the plate came out, night and day from when the unit was dropped off. 

Power Supply

The single assemblage PCB here plants the driver, tone and power supply all in one location. The power supply utilizes two 6800 microfarad capacitors in the rectification/driver filtering. This does use an interesting secondary in-line fuse array for protection as well. All capacitors here were upgraded with high temp long life panasonic FC/FR capacitors, general use diodes were replaced 

with modern UF4XXX series. The filter capacitors were replaced with 6800 microfarad Cornells.

Phono/Tone 

The RIAA consists of dual 7136 pick-up IC's, all electrolytics including small value tantalums were replaced with audio grade Nichicons and low impedance high reliability Nichicon PW's. Whats interesting in this topography is the attention in design to hi/low gain loss typical here and how they compensated in pre-amplication. 

Driver Assembly

The amplifier circuit consists of a pair of dual FET differential transistors in the 1St stage. In the final stage I want to highlight a upgrade that may be of some benefit for continued years of use, updating the output devices to a more reliable TIP41/42 TO-220 transistor package (2SB596/2SD526). The biasing procedure is effortless with easy to access (cept #36) "test points". For all electrolytics here Nichicon KA and KW audio grades and WIMA PP's were utilized.

RF (AM/FM) stages

Per my usual I think the Nichicon PW's really work great here, a nice reliable low impedance capacitor. Several tantalum capacitors in odd ball values are present and should be updated with electrolytics as well. 

New 8V 300mA lamps and a deep cleaning wraps it up, a very nice little side setup receiver.

Sansui 1000A Repair & Modification

Sansui 1000A Valve Receiver 

Here we've got a Sansui 1000A Valve Receiver. Their are a few variants of the 1000A/T topographies plus different bias configurations to note. 

This particular unit came in for extreme hum and red plating issues. A few modifications can/should be integrated as well. For  a more consistent reliable cathode draw or bias current a 10 ohm 1/4-1/2W MOX should be used at the 7591 power valve cathode pins to ground, remove the original jumper and replace. One can also tie the dependent bias potentiometers to a single control if desired. 

Another issue brought to my attention was the 117VAC original rating. If we look at the driver section schematic we see posted Vdc of 470Vdc+ for a plate voltage. Most modern homes here stateside operate in  120-125VAC range. Looking at initial Vdc rating we see peaks of 482/480Vdc. so increasing come capacitor voltages is a good here. 

7591 Pin-Out Configuration

For the red plating, after ruling out mismatched 7591 valves we look at the bias circuit. The grid resistors 1K and bias 200K resistors are typically out of spec on these units, another common fail point is the oil-type .3uf coupling capacitors. It is highly recommended to replace these with a 500Vdc+ electrolytic or polypropylene in the given voltage. I also recommend replacing electrolytic axials here as the axials in the time period in my opinion are dodgy at best.  Monitor again for about 30mA draw at the cathode resistor and that solves that. A thing to keep in mind, because of the auto-biasing 7591 topography, matched quads are of some benefit here. The 1st stage ax7's were fine but the consistent left channel hum was the result of a bad 6AN8 valve. 

BEFORE

New coupling capacitors (.33 630Vdc PP, new .47 & .22uf PP capacitors, new 30uf radial panasonic FC high temp long life electrolytic)

AFTER

Keep an eye out for our Sansui 1000A Restoration posts coming soon!

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"

http://www.maximumink.com/

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.

http://www.union.wisc.edu/WUD/music-events.htm

https://www.facebook.com/wudmusic

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 :)

http://www.liveonkingstreet.com/

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. 

http://www.capitolviewpresents.com/index.php#calendar

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!

http://www.olbrich.org/events/summerconcert.cfm

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!

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

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

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.

Stereo.de ~ Moderne Technik im Retro-Look