Magnavox console amp 6BQ5

Brad · « **on:** 20 Feb 2008, 05:59 am »

Not sure why, but one caught my attention on e*ay today.
So I am now the owner of a single-ended 6BQ5 amp, rated at I believe 5wpc.

Anyone familiar with these?
I am planning on using it to rebuild an antique radio for my wife.
Most likely using driving a pair of Hawthorne 10" coaxials built into the console.
Source will likely be a Squeezebox.

doug s. · « **Reply #1 on:** 20 Feb 2008, 04:33 pm »

Quote from: Brad on 20 Feb 2008, 05:59 am

Not sure why, but one caught my attention on e*ay today.
So I am now the owner of a single-ended 6BQ5 amp, rated at I believe 5wpc.

Anyone familiar with these?
I am planning on using it to rebuild an antique radio for my wife.
Most likely using driving a pair of Hawthorne 10" coaxials built into the console.
Source will likely be a Squeezebox.

i have no first-hand experience, but i have read that these will sound as good as multi-kilobuck rigs if refurb'd & modded w/upgrade parts. i'd post over on audiokarma or audioasylum or diyaudio for info...

doug s.

JoshK · « **Reply #2 on:** 20 Feb 2008, 05:27 pm »

That's a SE EL84 amp, I have the PP EL84 magnavox console pull amp. They will sound excellent as is and even a bit better with some re-capping and cleaning. It's really the beauty of the EL84 tube. It really is the hardest tube to screw up. Its easy to drive so the amp doesn't have to be complicated and its so damn linear it sounds good.

There are ways to improving it, but simple stuff is all that is needed.

acresm22 · « **Reply #3 on:** 20 Feb 2008, 05:44 pm »

If you do a search on AC, you'll find some posts by msgsxr...he bought a Mag seEL84 amp on ebay a few years ago and has raved about it.

Also, Gabe Velez builds some nice amps based on Mag circuits, and his website is a great source of info about all things Magnavox... http://members.tripod.com/~gabevee/

Gabe's most famous is the Mag 1515, which is based on a push-pull circuit. But his website has been advertising an seEL84 in recent years that looks very interesting...no pics posted, but he told me the chassis looks a lot like his 300B amp (only with el84s instead of 300Bs ; )

lcrim · « **Reply #4 on:** 20 Feb 2008, 05:54 pm »

Mark from Canada, mcgsxr has one for a while now and he lives in the Toronto suburbs. Bought it off eBay for a little and put a few bucks into it and has been happy w/ it. Send him a PM,and he'll be more than helpful. One of the best guys on this site.

Brad · « **Reply #5 on:** 20 Feb 2008, 06:17 pm »

Thanks for all the replies.
I forgot my co-facilator was the owner of one...

I found Gabe Velez' site, but only saw the push-pull version of the amp.

I'll post a picture of this console radio tonight - it has some really beautiful woodwork.

mcgsxr · « **Reply #6 on:** 20 Feb 2008, 06:21 pm »

Guilty as charged, I am the guy who bought a similar one, and have indeed raved about it!

Thanks for the good karma, all my AC friends, and Brad gets 40 lashes with the wet noodle for failing to memorize my system!

I have a schematic for the particular one I own, but Audiokarma is the place to go and post this exact stuff, there are lots of folks out there that know a ton about these.

There is also a Yahoo group called Friends of Magnavox, with a TON of insight around this. Gabe participates in the Yahoo group, so you might be able to ask Q's etc, and I am sure you will see lots of fun SE EL84 traffic along the way.

Nice catch, I am sure you will have fun with an SB3, and a pair of OB's with this little guy, I have been parked from upgrades for around 2 years now...

Brad · « **Reply #7 on:** 1 Mar 2008, 06:25 pm »

It's here.
A couple more pics

Looks like the speakers share a common neg.

Jampot · « **Reply #8 on:** 1 Mar 2008, 08:39 pm »

Quote

Most likely using driving a pair of Hawthorne 10" coaxials built into the console.
Source will likely be a Squeezebox.

Now that is the kind of 'squeezebox re-box' I like the sound of

Look forward to seeing pics and following progress.

Jim

Dmason · « **Reply #9 on:** 1 Mar 2008, 09:16 pm »

Look forward to Maggie Magic.

There are people out there who have settled on THAT amp, after rounding thru many high dog power houses.

ltr317 · « **Reply #10 on:** 1 Mar 2008, 11:55 pm »

I have a couple of Magnavox console amps. One is a heavily modified 88 series amp with 6V6 output tubes and the other one which I just got from ebay is a 93 series amp with 6BQ5/EL84 output tubes. I just sold the 88 amp to a friend who loves the sound of it. I have to clean the 93 amp and replace any out of spec components. You should join the yahoo magnavox friends group if you want to learn about these amps. Gabe is a frequent contributor.

JoshK · « **Reply #11 on:** 2 Mar 2008, 01:44 am »

Your 6V6 amp looks a bit like mine.

ltr317 · « **Reply #12 on:** 2 Mar 2008, 02:10 am »

Quote from: JoshK on 2 Mar 2008, 01:44 am

Your 6V6 amp looks a bit like mine.

What kind of wood did you use for the cabinet? A friend made the cabinet side panels out of Bubinga, from scraps he had left from another project. It's a beautiful wood when you look at it in person.

JoshK · « **Reply #13 on:** 2 Mar 2008, 03:07 am »

I haven't put it in a wood cab yet. I meant the layout and parts looked like it was like my 6V6 amp.

slbender · « **Reply #14 on:** 2 Mar 2008, 04:36 am »

We had a console back in the 1960's with that same amp. It had a 12" woofer one each side, and two front mounted tweeters for each channel, and went really loud on the 1960's type efficient speakers. I loved that set!~! When we moved from the house and could not take it along, I busted it up and pulled the amplifier out, still have it today. It was the inspiration 10+ years back for the rather complex SET Amp seen above my name to the left.

The original Magnavox amp used a 1/2 6EU7 and a 6BQ5 in each channel SE mode. Power is around 2 Watts per channel before distortion gets totally ridiculous. The power supply with a 6X4 dual diode if I recall, only had a thirty to fifty microfarads total, and its performance was rather mediocre. Using modern day speakers, its distortion travels back through the power supply causing IM in the opposite channel, it clips badly and really needs speakers in the 90dB+ efficiency range. Its limited in the bass, to say 100 Hz. due to the small OP transformers, but hey, its a nice little amp for its size...

-Steven L. Bender

Quote from: Brad on 20 Feb 2008, 05:59 am

Not sure why, but one caught my attention on e*ay today.
So I am now the owner of a single-ended 6BQ5 amp, rated at I believe 5wpc.

Anyone familiar with these?
I am planning on using it to rebuild an antique radio for my wife.
Most likely using driving a pair of Hawthorne 10" coaxials built into the console.
Source will likely be a Squeezebox.

ltr317 · « **Reply #15 on:** 2 Mar 2008, 04:50 am »

Quote from: slbender on 2 Mar 2008, 04:36 am

We had a console back in the 1960's with that same amp. It had a 12" woofer one each side, and two front mounted tweeters for each channel, and went really loud on the 1960's type efficient speakers. I loved that set!~! When we moved from the house and could not take it along, I busted it up and pulled the amplifier out, still have it today. It was the inspiration 10+ years back for the rather complex SET Amp seen above my name to the left.

The original Magnavox amp used a 1/2 6EU7 and a 6BQ5 in each channel SE mode. Power is around 2 Watts per channel before distortion gets totally ridiculous. The power supply with a 6X4 dual diode if I recall, only had a thirty to fifty microfarads total, and its performance was rather mediocre. Using modern day speakers, its distortion travels back through the power supply causing IM in the opposite channel, it clips badly and really needs speakers in the 90dB+ efficiency range. Its limited in the bass, to say 100 Hz. due to the small OP transformers, but hey, its a nice little amp for its size...

-Steven L. Bender

Quote from: Brad on 20 Feb 2008, 05:59 am
Not sure why, but one caught my attention on e*ay today.
So I am now the owner of a single-ended 6BQ5 amp, rated at I believe 5wpc.

Anyone familiar with these?
I am planning on using it to rebuild an antique radio for my wife.
Most likely using driving a pair of Hawthorne 10" coaxials built into the console.
Source will likely be a Squeezebox.

Hi Steve. I see you got home okay from last night's meeting. How did the amp shootout go? How did the Dassun integrated sound after you fixed the problem? Which amp did most people like the best? I would like to bring the modified pas to Mel's later this week and would like you to inspect it. Maybe you guys can find something because I didn't see anything wrong when I opened the case. Paul

slbender · « **Reply #16 on:** 3 Mar 2008, 04:47 am »

Hi Paul -

This should have been a PM, as it adds little or nothing to the thread about the small SE console amps, except that Paul has bought a couple of those small amps recently, at least one was a 6V6 PP type for upgrading; and I also own three low power Single Ended amps circa 1965-1969 Akai tape recorders, whose mechanical transports were simply - beyond repair.

To answer you question about the Audio Syndrome meeting at Andy's house... That big Chinese Integrated Dassun amp did sound nice, and was listened too under three conditions.... #1) connecting the output off the external DAC into the (Tube) VanAlstine Preamp -> into its own Preamp high level input; #2) The DAC output into the Dassun Preamp input; #3) The DAC output into the Main Amp input bypassing both the V/A Tube Preamp and the Integrated's solid state preamp.

Everyone who had an opinion - had the same opinion. Condition #1) sounded the best, probably due to passing the signal through the tubes of the V/A Preamp. Next best but sounding somewhat sterile was Condition #2) and least liked was Condition #3).

The Original configuration using the McAlister tube amps ( I don't know if they were borrowed just for the meeting, or what... ) was more to my own liking. Still, I think the old modified Heathkit tube Amp he had for many years had even better depth and a more musical sound. I don't know if he stored the Heathkit; or sold it, or what...

OK, on looking at the PAS, if I can get over there maybe Friday..

-Steven

Quote from: ltr317 on 2 Mar 2008, 04:50 am

Hi Steve. I see you got home okay from last night's meeting. How did the amp shootout go? How did the Dassun integrated sound after you fixed the problem? Which amp did most people like the best? I would like to bring the modified pas to Mel's later this week and would like you to inspect it. Maybe you guys can find something because I didn't see anything wrong when I opened the case. Paul

doug s. · « **Reply #17 on:** 3 Mar 2008, 04:29 pm »

Quote from: slbender on 3 Mar 2008, 04:47 am

Hi Paul -

This should have been a PM, as it adds little or nothing to the thread about the small SE console amps, except that Paul has bought a couple of those small amps recently, at least one was a 6V6 PP type for upgrading; and I also own three low power Single Ended amps circa 1965-1969 Akai tape recorders, whose mechanical transports were simply - beyond repair.

yup, off topic; now you have me doing it!

i have a pair of set el84 amps pulled from an akai m-8 tapedeck, & the sound is fantastic - rivals many way-more-spendy amps, & i have <$100 into them, which included shipping, speaker adapters for the 1/4" fone plugs, & a service manual to sort its connections out.

to get the subject somewhat back on topic, i can heartily recommend cheap wintage amps like the magnawoxes, etc, for excellent low-power tube sound...

doug s.

acresm22 · « **Reply #18 on:** 3 Mar 2008, 05:35 pm »

Hey Doug, hope you don't mind but I sent you a pm with some questions about your Akai amps. I have the Roberts version of these amps, but am having some connectivity issues.
Thx.

doug s. · « **Reply #19 on:** 3 Mar 2008, 06:00 pm »

Quote from: acresm22 on 3 Mar 2008, 05:35 pm

Hey Doug, hope you don't mind but I sent you a pm with some questions about your Akai amps. I have the Roberts version of these amps, but am having some connectivity issues.
Thx.

i answered your pm, but if you had set up your audio asylum account to notify you when someone replied to one of your threads, ya wouldn't have needed to pm me...

doug s.