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Saturday, July 15, 2023

Rotel RA-820 Amplifier

On my audio journey, in the early days I went through many Japanese amplifiers and receivers, including a Sansui (not the sought after versions), a JVC, then I bough a Harmon/Kardon (HK330i) receiver, finally bringing me to a Rotel AR-840BX that I bought in 1985.

I came across this little gem, a Rotel RA-820, from early 1980's. This was from a time of hi quality amplifiers for less money, and this amp competed against the NAD 3020, which has it's own cult following. There is a little history on the early Rotel series here.

Rated at 25 watts per channel and very much a minimalist amplifier that does not get in the way of the sound. Like the NAD and my earlier 840-BX these Rotels punch way above the rated watts per channel when turned up, lots of head room, easily doubling their rated RMS per channel.

This unit I picked up is in awesome condition from a guy downsizing his audio system. 





I currently have this running with the Dynaco A25's and this is a great combination for Hi-Fi. I always like the low watt entry level units, that are less complicated and offer great value. This Rotel was a great score and rare to come across in such great condtion.

Monday, October 31, 2022

Dynaco A25 Speakers

My keen eye spotted a local pair of Dynaco A25 speakers offered up locally with no labels on the ad, I recognized them by the backs of the speakers.

Back in 2017 I had a pair of Dynaco A25's and in 2016 I had a pair of Dynaco A35's and now I get this great pair of 25's to listen to again.

 





 

 This pair of A25's are in great shape with all corners square and the grills in perfect condition. The usual sanding and re oiling to cabinets will be in order. I currently have these hooked to my 2 watt tube amp in my office and I am loving them. 

The bass is better than the KLH Model 17's I have, on par with Advents that I have had in the past. I may replace the crossover cap with a new Solen one.

I am happy to have these speakers again and I think they will be sticking around for awhile.


November 11th update, I have replaces the original capacitor with a Solen polypropylene cap and sanded the cabinets, a coating of Circa 1850 Terra Nova Naturoil has brought the cabinets back to their glory.

The water stain is going to stay in one speaker and the small scratches have been smoothed out pretty good in the other.

 



 




Monday, October 3, 2022

Grundig Box 650B Speakers



 A rare pair of speakers to end up in Canada is this pair of Grundig Box 650B speakers. These came up locally and caught my interest. Like the A/D/S, Dual and Braun speakers that have graced my listening space in the past, these are another 3-way German speaker that has the massive mid-range dome.


 



One speaker had a small rip in the woofer cone and a pushed in dome on the mid-range. I fixed the rip and reformed the dome as best as possible.

Nice addition to the speaker experience.

August 18th update, these little beauties needed a repair to the tweeters, both were blown and these have been sitting is storage, I finally got replacement tweeters and these speakers sound phenomenal. Just like A/D/S, Braun, Visonik speakers in the pas the midrange is very open in these speakers with very good well rounded bass. These speakers are staying and match really well with a tube amplifier.

These are great speakers......

 

 

 


Monday, August 22, 2022

KLH Model 17 with Philips AD7060/M4 Full Range Drivers

 Because I can. When these KLH Model 17 speakers re-arrived in my possession I kept getting the idea to experiment with changing the drivers out.

 



 

I had scored a set of Philips AD7060 4 ohm fullrange 6 inch drivers from a thrift store a few years back and was waiting to find a home for them. I had heard great things about the Philips full range drivers and sold a similar pair of alnico versions on Ebay for a great price a while ago.

I have hooked the AD7060 to the tube amp and was impressed by the clarity and efficiency of these little 6 inch wonders, I just knew they where shy on the bass without a super large cabinet, this is where the Model 17's come in.

The Model 17's have a great tight bass from an acoustic suspension cabinet along with a fairly efficient 10" woofer that goes well into 40hz.

I opted to gut the crossover and remover the Model 17 tweeters and enlarge the hole to accommodate the AD7060 fullrange driver. I also opted not to use a crossover between the drivers as the KLH has a natural roll off around 1500hz and is a bit less efficient that the Philips. The AD7060 does not really shine until around 150-200HZ and is pretty smooth to 15,000HZ, about where the original KLH tweeter ran out of steam.

I love matching fullrange speakers with single ended tube amps, this is audio nirvana to me, you get to hear all the music. 

The changing of the tweeter to a fullrange Philips has made these speakers shine, completely opened up the sound stage, words can not convey the difference this change has made.




I know this would seem unconventional to most but I love the sound from this set up. I have been running off the four watt tube amp and wow! the sound is all there and loud enough.






 

Saturday, August 20, 2022

Innovative Speaker Designs ISD Spirit 0.25 Speakers

An interesting pair of mini speakers came my way, these Innovative Speaker Designs ISD Spirit 0.25, these see to be well made, locally in Kelowna BC. 

I do not have much information on them but once I saw that they were using Vifa drivers I knew they were of pretty good quality.

The real Rosewood veneer in great shape and the speakers seem really well built with Bennic polypropylene capacitors in the crossover. 

The Vifa woofer is 4.5 inches (C11SG-05) and a Vifa D19SD tweeter.

Not exceptionally low on bass of course, these would benefit with a sub woofer crossed at 150hz. The midrange and highs is where these speakers are at.

 




 

Pretty cool little speakers and a very nice little find locally.



Saturday, July 16, 2022

Electrohome Single Ended Tube Amp

 This little four watt single ended tube amp was returned to me after I donated it to a yoga studio that I trained at.

It was mostly recapped by David Yee in Vancouver and since I got it back I have done the large caps and cleaned the amp up, with a new paint job, got rid of the large capacitor can added the volume pot and on/off toggle to the top.

It really is amazing how just 4 watts can really sound! I love single ended tube amps and they seem to getting harder to find. This unit came out of an old console stereo.




I will sell this little amp so hit me up if interested.

An update:

Now complete with a nice wood case for it.






KLH Model 17 Speakers Returned

This pair of KLH Model 17 speakers made their way back to me after I donated them as part of a stereo system at a yoga studio that I trained at.






These are great vintage 10" two way speakers, I originally owned these in 2017 with the original blog postings to be found here and the recap pages found here.

Very similar the Henry Kloss Advents that I have had many experiences on this blog. 

I have them paired with an Electrohome Single Ended Tube amp that I also gave to the yoga studio.

These are a great sounding speaker and well worth searching out.