Primaluna Dialogue Premium Integrated driving Magnepan .7 with Bypassed Fuses


Hi everyone,
I am a relatively new audiophile, joined Audiogon 2.5 years ago, and this is my first post. I enjoy reading the forum very much, and would like to say thank you to everyone who has shared their knowledge, wisdom and humor with me. For this my first post I am looking for advice: I have a pair of Magnepan .7 speakers with bypassed tweeter fuses, and I am wondering if I can safely drive them with my Primaluna Dialogue Premium amplifier. The amplifier has 4 ohm speaker connections, and using KT120 tubes in ultralinear mode it produces 43 watts per channel (per specs). What I don't know is how much current it can provide the Maggies which I understand draw a lot of current (I have not seen an impedance curve for the speakers). My listening room (aka living room) is approximately 13' x 16' x 7',  with partially treated walls and corners. The speakers are on the short side about 3.5' from the back wall, I sit about 7.5' away from the speakers, and I listen to music at around 60-65 dB (C-weighted), sometimes peaks in the low 70’s. So my question is: am I taking an unnecessary risk driving the Maggies with the Primaluna? Can I damage the speakers if I play them too loud? In case you are wondering, after I bypassed the tweeter fuse and attenuator connections, the speakers sounder much clearer and precise to my ears in my room with my system.

 

 

classic8

You should be fine at those listening levels.  

Bypassed fuses are irrelevant.

Enjoy

Jerry

Personally, I would play the system for a few months with the fuses in place so see if there are any issues.  If you don't blow any fuses during this time, you should feel a little more confident bypassing them.

Your suggestion is logical. I am usually cautious with these things, and after a week I decided to take the risk and bypass the fuses. Hopefully I will not regret my decision, and I can still re-wire them back to the original configuration.

Some of the comments here think you're asking about bypassing fuses.  I understand that you've already made that decision and I'm sure you're experiencing better sound.  Fuses have no business in the signal path.  

I believe you question is just:  is 40 wpc enough to drive the Magnapan 7.1 at low levels.  My experience with large electrostatic speakers indicates the answer is  yes.

Jerry

Jerry is correct - I already bypassed the fuses (and attenuator connections). The speakers sound much clearer and precise to my ears in my room with my system. The main question was if my PL integrated at around 40 wpc could drive them without any risk of damaging them.

@classic8 : Hello… I had MG-1.7s, and now MG-3.7s driven by a Music Reference RM-10 amplifier (35 wpc), and I listen to music in a slightly larger room than yours, at slightly higher levels with no problem at all. I’m enjoying some of the best sound ever with this combo after many years of using Magnepans with many different amplifiers. You should be just fine. Incidentally, I bypassed the fuses in my 1.7s for years without issue. I haven’t done so with the 3.7s. Happy listening!

@classic8 : One caveat I’d like to mention… I use Speltz Zeros to double the impedance that the amp sees, and I’m using the 8 ohm output taps. I didn’t notice a big difference in sound, but it made me feel more comfortable with using a lower powered amp with low impedance speakers (electrically). 

@classic8 

40 watts is enough, but if you want to make the Maggie’s sing, hook up a subwoofer or two and set the crossover’s to sixty-eighty hertz.  By removing the bottom, 40 watts will make them rock!😁

All the best.

@classic8 : You’re welcome! To be clear… I used the RM-10 with the Maggies without them with no problem, but chose to buy them to make the amp/speaker synergy a happier one. Also, the designer of the amplifier (Roger Modjeski) was a strong advocate for “light loading” his (& other) tube amps. That would’ve been impossible without the autoformers. 😉

@curiousjim: Thank you for the suggestion. I have read that many Maggie users add one or more subwoofers. I am assuming you are suggesting adding an active crossover, or a subwoofer that has one built in?

@classic8 

Yep. I have Acoustat Model X speakers with 40 watt servo amps and with fresh tubes they play louder than I’d ever play them.  And while they will play down to 30 hz, because of their design they don’t have the they don’t have the umph and they draw most of the power. So I originally built pairs of subs with an active crossover and now use an SVS 2000 Pro subwoofer.  The software is great for dialing it in and my tubes aren’t driven as hard. It’s a win win for me.

@krelldreams: Have you heard the Music Reference RM-200? Modjeski designed that amp to be unique in two regards:

1- Produce 100 watts (per channel) from a pair of KT-88’s or 6550’s.

2- Play well with low impedance loads (like Maggies). The output transformer taps are 8 ohms, 4 ohms, 2 ohms, and 1 ohm!

 

@curiousjim: Modjeski was a big fan of the Acoustat panels, less so of the original dedicated amp and even less so of the transformer that replaced it. He designed an amp specifically for the Acoustats; perhaps @clio09 can tell you all about it if you are interested.

Acoustat Model X’s came with the servo amps screwed to the bottom each speaker. The later amps I believe will work with any speakers.

@bdp24 : Yes, I bought a NOS RM-200II from Music Reference shortly after Roger passed. I had a few conversations with him over the phone prior to that purchase, and some more via email. He asked about my specific system, listening habits, room size & set up, and associated equipment. He was very generous with his time, answering all my questions, asking me questions, and it seemed like he was truly interested in getting me the right fit(s). He told me how he specifically created the RM-200 for Magneplanars and other such speakers. But during those conversations he hinted that he held the RM-10 in higher regard overall. He told me that the RM-10 should be fine driving my Magnepans taking all that I told him into consideration. It was hard for my brain to accept that the 35 w/ch RM-10 could drive my large speakers adequately. I did buy a used RM-10, but I used it in another system. A year later, I bought the RM-200II from Tony at Music Reference and I was very pleased. I lived happily with that amp in the system for awhile until a power tube went & I didn’t have matched spares (ALWAYS keep spares!). I put a vintage tube amp that I kept as a backup in the system as a stop gap so I could listen to music. The amp is a HH Scott LK-150 (~60 w/ch). It sounded awesome in place of the RM-200, and the 60 w/ch was plenty for my room. That made me feel compelled to place the RM-10 in the system. Could this little 14 lb amp drive these giant speakers? Yup.. sure did. And as wonderful as the Scott sounded, the Music Reference was even better! When the new tubes arrived for the RM-200, I installed them, biased the amp, and left it in the system for a few months. It, of course, sounded great! One week when I was on “staycation” I conducted a 3 way amp shootout. The 3 amps all sounded amazing to me, with the RM-200 on the “almost too SS sounding” side, and the Scott on the “almost too tubey sounding” end. The RM-10 was right between them… “just right”. I’ve used a bunch of amps with several Magnepan models over the past 35 or so years, and this is about the best sound I’ve had in my house. I once had a Krell KSA-250… I should’ve never sold that one. I’ve been chasing that feeling of satisfaction for years. I believe I have that feeling now. As I wrote earlier.. I bought the Speltz Zeros so I could “light load” the RM-10 as Roger suggested. In the end, the man was right on. I should’ve taken his hints as an endorsement. He was clearly not trying to “sell me”, but steer me in the direction he thought was right for me. 

Great post @krelldreams!

I’ve heard of some guys using the RM-10 strapped for mono, in pairs. I went to the RM-10 release event at Brooks Berdan’s shop in Monrovia, where Roger discussed the design of his little amp. After the talk I spoke with him for a while, and asked him if he recommended a pair of RM-10’s for use with stacked Quads (which I at that time had), or a single RM-9 instead. He said the RM-9, for its’ greater headroom..

The next time I saw him he told me he had been thinking about my question, and had actually changed his mind; he now would recommend a pair of RM-10’s over a single RM-9. I think I remember @clio09 saying the RM-10 had become Roger’s favorite push-pull amp of his own design. I use one with my Quad ESL’s (a single pair, not stacked). Being a Roger Modjeski fan boy (a badge of honour ;-), I have all three of his push-pull amps: an RM-9, -10, and -200, all Mk.2 versions.

@bdp24 : Yes, I’ve read many of your posts over the years. The RM-9 is an amp I’d love to try one day! Also, I’ve been considering possibly getting my hands on a pair of the ET LFT-8b speakers that you and others have written about… but I don’t have any complaints about my current set up, so why fix what ain’t broken? The RM-10 is definitely a special amp (imo), and I would recommend it to anyone who values quality over quantity. Within its limits, limits which have proven to be surprisingly broad, it’s hard to fault. The OP described what I consider to be a great environment for this amp. I’m sure the Prima Luna he asked about would be fine too (in terms of power), which is what prompted me to chime in. 

Just wanted to report back - very happy with the sound of the .7 Maggies driven by my PL integrated :)

@classic8 : I’m very glad to hear that you’re enjoying the sound of your system. In the end, that’s the most important thing, isn’t it? I’ve found Magnepan speakers to be special… not everyone’s cup of tea, but special for those who appreciate what they do differently from conventional speakers. Also, after reading your initial post, I strongly believed your amp would power them well. Happy listening!

@krelldreams: Thanks! Yes, as in life, is is wise to enjoy the present moment making do with what we have. I may be new to this hobby, and like other audiophiles I am constantly thinking of future changes and upgrades. But if we just focus on the future we miss out on the present.