Magnavox 9302-00 EL84 tube amplifier

Another win on Ebay is this top of the line Magnavox 9302-00 push/pull EL84 tube amplifier. This unit will run around 15WPC when completed. These were units pulled from console stereo units from the mid 60's. This unit will get all the capacitors and resistors replaced along with a whole new tube set.

There is lots of support for this amplifier over on AudioKarma discussion boards with David Gillespie leading the forum.

This is my third vintage console push/pull EL84 amplifier with the first being the Electrohome Lorainne 40.

And this RCA RS-177J push/pull EL84 tube amp. 

Although this is a speaker blog, I have enjoyed working and learning about tube amplifiers. Tubes are my preferred way to enjoy the music and these older tube amps are easy to work on since they are point to point wiring and really basic in their layout. Schematics are easy to find as are the parts.

RCA RS-177J Tube Amplifier

 This blog has been super quiet as of late due mostly to Covid and my current space that is not as conducive for expansive audio experience and restoring. That being said I am still finding gear, although much harder to find and it is in storage until a later date.

This nice RCA RS-177J tube amp made my way to me through an Ebay win, the amp was in pretty rough looking condition and needed a serious overhaul including new capacitors, resistors and a general cleaning and a paint job.

This amp seems to have a good reconditioning following on the audio forums, but I mostly followed Mark Walker at Blue Glow Electronics walk through including the front end hot rod modification in changing out the 6FQ7 input tubes to 12AX7 input tubes.

He has a few videos also on the restoration of the RS-177A version of this amp.

I followed Mark's instructions and managed to get this tube amp sounding great. I got all new JJ tubes from the Tube depot.

This amp is from the top of the line console stereos that RCA made in the early 1960's and runs around 12 watts per channel in a push/pull configuration.

These RCA's are worth sourcing out as they are easy to restore and there is lots of info on these. This one is a gift for my son for his 21st birthday, something  he can enjoy for another 50 years.

Advent/1 Speakers

A recent trip to Vancouver yielded this pair of Advent/1 speakers from a local thrift store. I have had many Advents Speakers come my way including the Advent 5012, the New Large Advent, the Smaller Advent, the Baby Advent, the Advent 2002 and a pair of Advent 2W that were in my possession before the birth of this blog. Needless to say I have been a big fan of Advents along with EPI speakers as both are well designed 2 way acoustic suspension speakers.


This pair is a later version with the metal woofer basket but still with the fried egg tweeter. New foam surrounds were needed after 40 years. The cabinets are real wood veneer and I would rate them a 7 out of 10 at this point. These definitely needed some serious dust cleaning at this point.

 I really like  this set of Advent/1 speakers and they remind me of the New Large Advent I had but the cabinet is not as nice and the bass extension is close but not as deep as the New Large Advents, the rest of the speaker has the same acoustic signature as its' big brother.

I am currently running these off my Electrohome Push/Pull tube amp and I am really pleased with the detail of the sound plus the warm deep bass that these are known for. Although I am a big open baffle fan I will keep this pair of speakers around for a bit, these are easily my favorite 2 way 10 inch speaker that I have come across. Just to note that the EPI 100 are my favorite 2 way 8 inch speaker.

There is plenty of opinions on how these speakers won accolades in the 1970's as one of the best speakers for the money. I would tend to agree that these are great speakers and I am pleased as punch to come across a pair, Way to go Henry Kloss.

Foster Open Baffle Speakers

The latest open baffle speakers I have put together is a 3 way Foster driver speakers. The donor driver came from a pair of Noresco NEC-571  plus a horn tweeter that I picked up from a set of Zenith Allegro speakers.

This project turned out to be spectacular with the push/pull tube amp, almost in the league of openness and fullness as the Speakerlab Super 7's, almost. The Super 7's are really an amazing loudspeaker.

 The original Noresco speakers used a 10" Foster 25E33 alnico woofer with a massive magnet assembly crossed over to the Foster 8F3 three inch full range speaker. The original crossover was used as the crossover point between the woofer and the full range driver is around 650hz.

A foster horn tweeter was included to handle the high end as I found the 8F3 seemed to roll off in the highs.
A 2.2uf cap was used with a crossover point at 9000hz, it seems to have added the high end depth and sizzle that I like.

This combination came out way better than expected. Bass is full and clear, the mid range from the 8F3 is luscious and smooth, very deep and wide. the horn tweeter takes care of the highs in spectacular fashion.

Before I started this project I had an idea as to how this set up would sound, but it came out way better than I expected.

If this is what open baffles are supposed to sound like, then I am a believer now.

Aesthetics came out beautifully with the dark mahogany veneer.

Speakerlab Super 7 and a Push Pull Tube Amp

This has been the cause of the lack of postings for the past month.

Audio nirvana has hit with the combination of the Speakerlab Super 7's and the push pull tube amp.

It has evoked a minimum of 2 hours an evening of listening with a few solid 12-14 hour days of non stop music thrown in.

At this point in the journey, not to much can touch this combo.

Electrohome Lorainne 40 Push Pull EL84 tube amp

Another piece of fine audio equipment came home from the same place as the EMI 630 speakers, this 20WPC Electrohome Lorainne 40 push/pull tube amplifier.

This unit has had some previous work done to it with separate volume pots, handles on the side and feet attached to the bottom.

The 12AX7 tubes are Mullard/Amperex tubes that flash upon start up.

So I now have the best of both worlds with an Electrohome Marseilles Single Ended tube amp and this Electrohome Push/Pull.

On first impressions the Electrohome P/P is much louder and can drive all my speakers to a pretty decent decibel level where as the Electrohome SET can only push my most efficient speakers to the 98-100db level, which is plenty loud.

I was expecting more bass from the  and the bass that is there is well controlled, the mids and highs are clean and transparent along with the imaging. Where I find the biggest difference is the open and luscious mid range and highs that the Electrohome Single Ended offers up, it just can not be beat. Once the mids and highs are this good the three dimensional imaging is spot on with a single ended tube amp.

There is a fantastic write up called "Single Ended vs. Push Pull: The fight of the Century" by Eddie Vaughn, it is a good overview of both amplifiers.

Just like the analogue vs. digital, New England vs. West Coast, solid state vs. tube and single ended vs. push pull you will get diehards defending either argument.

So, where does my bias lean towards? I seem to like the pure Class A sound of a single ended tube amp more than the Class A/B of the push pull, both are great but the Single Ended just nudges out the Push/Pull with the open mid range and sparkling highs.