Maggie 197 SQ? (vs Scott 222-d?)

concertfiend

Active Member
Hi all, I have an eye on a Maggie console pull (6BQ5 SEP from what I understand). It looks to be rebuilt well, with 5 way binding posts, gold plated RCAs, and a volume knob. Apparently it has had some mods done to it too. It has some schematics and service paperwork provided. What I'm wondering is how good the sound quality is , and what I could expect from this amp. I have a Scott 222-D that I like quite a bit, how would this compare? I know it's about a third the power, but that's about it. The Scott is 7189 based. I'm new to tubes and curious about what difference a SE amp would bring, though I know theres a varying degree of them. Any info is appreciated!
Thank you
 
Realistically, you are just going to have to find one, listen to it, and compare them to one another. :bye:

Everybody's ears are different and you will soon discover that there are thousands of combinations of SE and push/pull amps and speakers that work well with each other. For the SE amps, you are going to need very efficient speakers. Now the fun starts. :thumbsup:

Took me 10 years to find my right combo and its hasn't changed in 4 years and its not going to. :music:
 
Realistically, you are just going to have to find one, listen to it, and compare them to one another. :bye:

Everybody's ears are different and you will soon discover that there are thousands of combinations of SE and push/pull amps and speakers that work well with each other. For the SE amps, you are going to need very efficient speakers. Now the fun starts. :thumbsup:

Took me 10 years to find my right combo and its hasn't changed in 4 years and its not going to. :music:
Yes, so many flavors, so little time.. .I have two pairs of efficient speakers - Klipsch Tangent 400 (97dB) and Pioneer PAX-30G (103dB) and hope to get some Altecs in the not too distant future. So while the amp is probably around 5wpc (SEP not SET if I'm not mistaken ), I should have enough power. Looks like I might do a straight trade for a Luxman R-1040 receiver. The amp has extra tubes and seems to be well modded to my basic knowledge.
 
Yes, so many flavors, so little time.. .I have two pairs of efficient speakers - Klipsch Tangent 400 (97dB) and Pioneer PAX-30G (103dB) and hope to get some Altecs in the not too distant future. So while the amp is probably around 5wpc (SEP not SET if I'm not mistaken ), I should have enough power. Looks like I might do a straight trade for a Luxman R-1040 receiver. The amp has extra tubes and seems to be well modded to my basic knowledge.

I have a Maggie 197-00 and it's a really nice amp. I've never heard of the SQ designation. One thing to keep in mind is that the output transformer secondaries are designed for 3-4 ohm speakers according to the Sams schematic. They will work with 8 ohm speakers but will lose a bit of power, I believe, but should still have plenty of power for your speakers. There's no harm in using 8 ohm speakers, it's just not optimum.

If you can find out the details of the mods done to the amp it would be helpful. These are pretty basic amps but I would expect new power supply caps and coupling caps at a minimum.
 
That's right. I almost forgot about the Magnavox output transformers being 3.4Ω.

Not sure if they are all the same but this is one from a Magnavox AMP-135. It is a push/pull transformer not a single ended and is just shown for reference.
MAGNAVOX AMP 135 - 3.jpg

Since your speakers are 16Ω, maybe forget about Magnavox and look for another brand that has multiple output taps like Scott, Fisher, Lafayette to name a few.
 
That's right. I almost forgot about the Magnavox output transformers being 3.4Ω.

Not sure if they are all the same but this is one from a Magnavox AMP-135. It is a push/pull transformer not a single ended and is just shown for reference.
View attachment 1354842

Since your speakers are 16Ω, maybe forget about Magnavox and look for another brand that has multiple output taps like Scott, Fisher, Lafayette to name a few.
Well I already got it. I'm not too worried about it , I can always sell it if I don't like it. I could try hooking it up to my Tangent 400 which are essentially Heresy IIs and 97 dB efficient. I also have some nice Tannoys that are 6ohm nominal and I think they're about 92dB.
What would happen if I do hook it up to the 16 ohm Pioneers? And if I swap for some 8 or 16 ohm trannies, is it drop in or does the circuitry have to be modified ?
 
I believe the Magnavox 197 is the top of the line for that series of amp. ( like the 196....) Don't know what the SQ is ?

The 197 is the one that Bob Carver modded I think.
 
Well been playing it with the Klipsch Tangents...still forming my opinion, but for now I would say it's definitely not as "full" as my Scott. Might be my first external Xover and sub project? I also don't think I like my Klipschs as much as the Pioneers anyway... Is there any reason I couldn't hook up the 16 ohm Pioneers to the 4 ohm Maggie transformers?

A little info regarding the build of it -
All signal path caps replaced (saw some orange drops and some others)
Gold plated RCAs and 5 way binding posts
Unnecessary wiring removed
1 Meg balance control replaced with 2 470K resistors
New power cord and switch added
Oak frame and rubber feet added
Currently using two Zenith 6BQ5 output tubes, Magnavox 12AX7 preamp and 5Y3 rectifier
Also included was a service receipt that states "bypass feedback network to clean up bass performance" and "remove unnecessary resistor from output "

00V0V_i7MAe96drdD_1200x900.jpg 00p0p_1ZJswtVrMDP_1200x900.jpg 01212_5ITvQPf6OKM_1200x900.jpg Screenshot_20181212-195256.png
 
That particular Magnavox amplifier would sound good with Klipsch Cornwalls or LaScala I would figure. Klipsch Tangents may require more "grunt" than the little Maggotbox can manage, and that's why the Scott with more wattage and larger output transformers has a fuller sound...it's a guess...

I doubt you will harm anything by trying 16 ohm speakers with the Magnavox, it might not sound good...but who knows? Try it real quick and see...

Have you tried the Scott integrated with the Pioneer speakers using the 16 ohm taps?
 
That particular Magnavox amplifier would sound good with Klipsch Cornwalls or LaScala I would figure. Klipsch Tangents may require more "grunt" than the little Maggotbox can manage, and that's why the Scott with more wattage and larger output transformers has a fuller sound...it's a guess...

I doubt you will harm anything by trying 16 ohm speakers with the Magnavox, it might not sound good...but who knows? Try it real quick and see...

Have you tried the Scott integrated with the Pioneer speakers using the 16 ohm taps?
Yeah that's what I figured , even with their high efficiency the Tangents are still rated 150w RMS 300 peak if I remember right ...hearing loss anyone? Had em hooked up to a 160wpc Carver receiver and one time I tried to see how loud it would be before the amp clipped. ..couldn't do it, it was intolerably loud. But I digress - after getting numerous audio "upgrades" I'm not so in love with the Tangents, they can seem a little shouty /harsh and overall they don't quite disappear or throw a large sound stage . As for the Pioneer PAX-30Gs hooked up to the Scott 16 ohm taps, that's my current favorite listening setup. I went in depth with a recent post I made about the speakers, but in short the synergy is nothing short of incredible to me! Even in the small room that setup is in ,it sounds like a concert hall :music:
 
Oh man, my main tube speakers are 16 ohm will that work ok?

I don't think running 16 ohm speakers will harm anything but they present a non-optimal load to the output tubes. The primary of the OT is 6.5k. When you run 8 ohm speakers it effectively doubles the primary impedance and using 16 ohms will, presumably, double it again. Someone correct me if I'm wrong.

So that would be a 26k primary for a tube that should be loaded between 4.5k and 7k, according to the data sheet. Some of the more knowledgable members can explain the technical effects it would have on the tube. From what I understand, going higher in primary impedance will reduce power output and also reduce distortion.

If you have two pairs of 16 ohm speakers you could run them in parallel, which creates an 8 ohm load. Or use two pair of 8 ohm speakers and get a 4 ohm load. That's what I do with a DIY amp I built that uses 4 ohm OTs pulled from a console amp.
 
I don't think running 16 ohm speakers will harm anything but they present a non-optimal load to the output tubes. The primary of the OT is 6.5k. When you run 8 ohm speakers it effectively doubles the primary impedance and using 16 ohms will, presumably, double it again. Someone correct me if I'm wrong.

So that would be a 26k primary for a tube that should be loaded between 4.5k and 7k, according to the data sheet. Some of the more knowledgable members can explain the technical effects it would have on the tube. From what I understand, going higher in primary impedance will reduce power output and also reduce distortion.

If you have two pairs of 16 ohm speakers you could run them in parallel, which creates an 8 ohm load. Or use two pair of 8 ohm speakers and get a 4 ohm load. That's what I do with a DIY amp I built that uses 4 ohm OTs pulled from a console amp.
Charlie,
I've been doing some digging and most of what I could find comes from tube amp discussion from guitar forums. A couple people go into detail how higher impedance is bad for tube amps, and lower is bad for SS. In short, voltage kills OPTs, while heat /current kills transistors. If the current is higher (lower impedance) than the transistors are rated for, they will fry. If the impedance load is higher than what OPTs are rated for, there will be more voltage than what they are meant to handle. This is why you always need speakers hooked up to a tube amp if it is turned on, having no load hooked to the taps means that the load is theoretically near infinity ohms. Now, depending on quality of trannies used, there seems to be some forgiveness - to the point that many people on the forums say it wouldn't be a problem other than having less power and possibly affecting sound quality as you pointed out. A 4 ohm tranny will probably be fine with an 8 ohm load for a long time, and a decent one will be ok with 16 ohm speakers too but it will slowly start to burn them out I imagine . Again, this is just me parroting what I learned in the last day or so, so if I'm wrong somewhere and someone else wants to chime in with their expertise or experiences , please do !
 
Unfortunate it is that your speakers are 16 ohms. There is no real way to get around your dilemma with the speakers and the MagnaVox amp. As others explained though it would not be catastrophic to use the two but it seem you should probably get an SE amp with 16 ohm taps. The EICO AF4 comes to mind but those are rare and getting quite pricey. I am not sure if your amp can accommodate new transformers so that is also problematic. I have Altec 19 speakers and my little "maggie" sounds very nice on that .
 
Hi all, I have an eye on a Maggie console pull (6BQ5 SEP from what I understand). It looks to be rebuilt well, with 5 way binding posts, gold plated RCAs, and a volume knob. Apparently it has had some mods done to it too. It has some schematics and service paperwork provided. What I'm wondering is how good the sound quality is , and what I could expect from this amp. I have a Scott 222-D that I like quite a bit, how would this compare? I know it's about a third the power, but that's about it. The Scott is 7189 based. I'm new to tubes and curious about what difference a SE amp would bring, though I know theres a varying degree of them. Any info is appreciated!
Thank you
It seems from your posts that you have already compared the 2 amps on your speakers. But it is not quite a fair comparison since the Magnavox amp requires a speaker load that is 4 ohm. So, since you want to keep the speakers i suggest you upgrade your OPTs. A long time ago i built an SEP amp based on the EICO AF4 schematic. For that project i acquired some output trannys from Heyboer which supposedly built the originals (or had the blueprint) for the AF4, and it could be ordered with the speaker impedance taps of your choice. Those OPTs were nearly the same size as the originals on the little mag. I know Heyboer keeps the design for the trannys they make on file, so you could order a pair and replace the 4 ohm units in yours. It may require some circuit tweaking but it should be close to a drop in fit.
 
It seems from your posts that you have already compared the 2 amps on your speakers. But it is not quite a fair comparison since the Magnavox amp requires a speaker load that is 4 ohm. So, since you want to keep the speakers i suggest you upgrade your OPTs. A long time ago i built an SEP amp based on the EICO AF4 schematic. For that project i acquired some output trannys from Heyboer which supposedly built the originals (or had the blueprint) for the AF4, and it could be ordered with the speaker impedance taps of your choice. Those OPTs were nearly the same size as the originals on the little mag. I know Heyboer keeps the design for the trannys they make on file, so you could order a pair and replace the 4 ohm units in yours. It may require some circuit tweaking but it should be close to a drop in fit.
That's good to know, thanks. I'm pretty new to soldering but I'm willing to try some minor tweaking, gotta start somewhere right? Maybe I should figure out how to change the title of this post since it's kind of changed course . It would be nice if one of the real experts like Gordon or Frannie weighed in on ease of changing the OPTs. Maybe they even have some spares around I could buy from em ...and I haven't actually compared the two amps with the same speakers, though I'm interested to at least try the Maggie on my Pioneers. But I've only used it on the Klipschs which I don't like as much. Hoping to get an Altec Onken build soon, there's a pair local here that's been sitting on the List
 
Output trannys are relatively straightforward. The OPT has a primary side , for SE 2 or 3 wires (if there is a screen tap) , 1 wire to the power supply and 1 or 2 wires to the tube. The secondary has 1 ground and the speaker impedance taps. It is just unsoldering the old wires and resoldering the new ones. Of course there are things you need to be aware of which are nothing really major. If memory serves, the Heyboer trans were about 60 bucks a piece.
 
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