Jan 6th, 2015 Posted in 1000A, Sansui | No Comments »
Sansui made a number of iconic receivers during their run as one of the top audio producers in the world. One of those is the classic Sansui 1000A. The 1000A is a tube receiver is known for its big and powerful sound. The A revision added bias adjustment for the 7591A output tubes. The receiver pushes out 40 watts of clean power per channel.
The phono section does use transistors but the two top level inputs and the tuner are all tube. Unfortunately the phono section uses old germanium transistors which are somewhat difficult to replace since there aren't really modern equivalents. It can be done however. I know that some people will utilize a small outboard phono preamp and use the tape monitor loop instead.
Speaking of old parts the 1000A's also have old oil filled capacitors in them which when powered up for the first time after many years can have explosive effects. Best case would probably be to replace them all but you could also bring the receiver up to power very slowly with a variac. Still, I think most would agree that replacement is the best course of action.
An interesting feature of the 1000A is that the low frequency filter works on the aux and tuner. Usually it is only used on the phono circuit to remove record rumble. It also has both Presence and Loudness switches which seems a little redundant.
Some of you may already know this, but the real secret behind the 1000A and many other Sansui audio products is their use of Hashimoto transformers. Hashimoto Electric was started in 1958 and has built high quality transformers practically ever since. Sansui was one of their main customers so many of their products have Hashimoto iron in them.
The Sansui 1000a came with a metal case but many user removed it due to the large amount of heat that the unit generates.
The 1000 version is much harder to find than the 1000A and there are actually a few different versions of the 1000A as well. The 1000 was only made for a year before revisions were made and the 1000A came out.
Some feel that the Sansui 1000A is the best sounding tube receiver ever made. That's saying a lot when comparing it to the popular Fisher 500C or 800C. Nonetheless, it definitely performs to high standards which means it is also in high demand. Run of the mill working units sell for around $500 while fully restored units can sell for $1200 or more.
Dec 16th, 2014 Posted in Rotel, Rotel RX-1603 | No Comments »
This one is a monster! It's the Rotel RX-1603 and is the biggest receiver they ever made. It earns its way into the Monster Receiver hall of fame by churning out 180 watts per channel into 8 ohms. It was made in Japan and would set you back a hefty $1100 when it hit the market in 1976. You would probably have to have someone help you get it to your car because it weighs in at a plump 73 pounds!
It has a beautiful white/amber glow that emanates from the dial face, FM tuning meter and signal strength meter. I wouldn't necessarily call the receiver aesthetically pleasing because it has somewhat of a robotic look to it and the alternating knobs and switches give it a mechanical Morse Code look.
The Rotel RX-1603 didn't just perform at high levels it was also built with exacting standards. It featured top of the line Sanken 2SC1586 output transistors that were hand picked and hand tested. It has 22,000 x 80v power capacitors that are as big as beer cans as well as a specially designed toroidal transformer made just for the RX-1603.
Another interesting feature of the RX-1603 is that it can be separated into two units, much like the Sansui G-33000, so that it will fit in more confined spaces. At 60cm wide, 18 cm high and 55 cm deep it won't fit in most cabinets or shelf spaces. But, with the special RK-100 separation kit you can break down the unit into two pieces and stack them. It saves about 27 cm in depth. Of course, nowadays that kit is very hard to come by.
Because the unit can be split into two pieces the designers located most of the inputs and outputs at an angle on top back of the receiver itself. The speaker outputs are located on the back of the amp section. There are outputs for three sets of speakers.
While the Rotel name may not be as well know as Pioneer or Sansui it has held its own with regards to price. Both the Pioneer SX-1250 and the Rotel RX-1603 run about $1100.00 when fully restored. Of course, unrestored units in good working condition sell for less at around $600 to $900. So, if you want to veer a little bit away from the mainstream and want monster receiver power then the Rotel RX-1603 just might be the receiver for you.
Sep 23rd, 2014 Posted in Kenwood, KR-9050 | 2 Comments »
Many audio enthusiasts consider a monster receiver to be one that puts out 100 watts per channel or more. Well, this Kenwood KR-9050 puts out just that - 200 watts per channel. So, I guess it would be considered a monster receiver. It certainly has the size at almost 2 feet wide, over 18 inches deep and over 52 pounds! Still, the KR-9050 probably takes a back seat to the KR-9600 that collectors are the most fervent over. I'm not sure why because the 9600 has some design issues that can be difficult to overcome and only puts out 160 watts per channel. Perhaps it's that the KR-9600 so firmly established itself as the top of the line receiver for Kenwood it overshadowed the KR-9050 when it came out. The KR-9060 is really just a KR-9600 with a bronze faceplate.
The Kenwood KR-9050 is the largest and most expensive receiver ever built by Kenwood. It is also the most powerful at 200 watts per channel with only 0.02% total harmonic distortion. And, of course, Kenwood produced some of the best tuners ever. With its Quartz Lock, adjustable IF bandwidth and two-level Stereo Sensitivity there really isn't much more you could ask for in a tuner.
The KR-9050 is stuffed full with features and has analog meters spanning practically the entire length of the front of the receiver. It also has a 1/4 inch MIC input with its own level control so you could even play your guitar through this receiver though I don't know if I'd recommended it. The only drawbacks to this receiver are that the switches are made of plastic and the knobs are plastic as well with metal caps and are not crisp in their operation.
Wow, look at that massive toroidal transformer! It's actually larger than the transformer in the Pioneer SX-1250. Also, notice the large heatsinks that take up about a third of the inside of the unit. As many audio techs know the KR-9600 has issues with both the power switch as well as the TA-200W power packs and Darlington transistors it uses which are prone to failure and replacements are virtually unobtainable. In contrast, the KR-9050 doesn't use the TA-200W or Darlington parts and is built with more easily replaceable parts. That is important if you plan on doing a restoration. A Kr-9600 that needs a resto is a totally different animal than a KR-9050 that needs the same.
Kenwood receivers are a site to behold when fully lit up and the KR-9050 is no exception. It is definitely one of the nicest looking receivers in the dark.
Being a true monster receiver the Kenwood KR-9050 is not cheap. It's not very easy to find either and is probably more rare than the KR-9600. I've seen one sell for $1500 but I've seen a few listed at over $2000. That's a pretty big chunk of cash for a receiver but if you're a Kenwood fan and want a holy grail receiver from them then this might just be the one.
Here's a video showing the massive Kenwood KR-9050 in action: