My initial thought is that you will have a hard time finding an inexpensive tube amp that will drive speakers that are only 86dB efficient. Not being an expert on the electrical side of things, though, perhaps others will have some more concrete suggestions. |
I agree with Learsfool. To implement tube amplification properly, you would have to rethink your speakers and replace them with a model that was more sensitive (at least 92dB, IMO) and with a flat impedance curve (preferably *minimum* 6 ohm nominal, with a low impedance not below 4 ohms).
The Fritz Grove speakers are not going to be a good match with a tube amp.
Also, you will undoubtedly receive some recommendations to implement a tube preamp to get some tube flavor. I disagree with this approach. It's a poor substitute for what you're really after, which is tube amplification. |
60 Watts should be plenty of power to drive the speakers in that room. |
Your speakers have an 8 ohm rating, a minimum recommended power of 25 watts from the manufacturer and your room is very small. You shouldn't have any problems at all. |
Why not contact Fritz and ask directly from the manufacturer; never heave dealt with them but would hope you'd get a transparent answer |
My Phase Tech PC 6.1 Two way base mounted speakers are 85 db... 8 ohms. Every tube amp I've owned has been able to run these units without issues.
The 'big deal' here is two fold... #1. speaker impedance.... 8 ohms nominal is a pretty easy load for most any tube amp. #2. Listening levels by prefference is a whole other world.
I suspect the above points are accurate and moderate powered tube amps ought to do fine there for you. Wethere or not you'll acheive 92db at your listening position is still one more story. SPL is the result of both the spaker abilities and the amps output. While you may have sufficient power to gain yourself , 92db at your chair, can the spaeker output those levels with aplomb?
I'm thinking they ought to come close if they don't. I'd opt for an amp with 75wpc and up.
the last thought is the 'tube' sound. it's relative you know? Differing tubes equate to differing views on the sound.... most all tubes though allow for a bit more rounding of the notes, and a skosh less razor edged approach to the notes, and usually much better decays. How sweet, fat, lush, romantic, full, and/or palpable the sound winds up being is on you.
As much as I enjoy tubes, and thtat took a while for me to discover, not every genre and style of music is best replayed by tube amps... IMHO. I feel they come close enough for me however, once you have the proper tube arrangement on hand, but I'd offer too, some music does better generally speaking, with SS amps inline.
I say this as the softness of your speakers (akin to my own 85db) might require you to do some serious rolling, or exchange your speakers for more incisive ones... down the road..... maybe.
My setup enables me to enjoy every musical genre quite well indeed. yet, a strong and very nice SS amp now and then is a real plus thing to have around at times, depending on the mood & musical selections.... ie., Little Feat... Def Lepoard... Queen... Rush... Joe Satriani...
Enjoy the ride and good luck. |
I'd find out from Fritz the minimum impedance specification. If it's within two or three dB of 8 ohms, then you might get away with a push-pull tube amp, but I would buy as much power as you can afford. Closer to 100 watts the better.
The problem you run into with an uneven impedance curve and tube amps is unbalanced volume between bass and treble frequencies because more decibel watts (dBw) are put into the highs and mids than are put into the bass, which results in the common complaint of the sound being "too bright".
If the speakers have a relatively flat impedance curve, then this is not an issue. |
I use 50 watt amps with 82 db spendors with no problem.Take the plunge the water is fine! |
In my bedroom system, I use a Jolida 102b (20 watts/channel) to drive Totem Model One Signatures (87 dB, 4 ohms) at low to moderate levels. With various upgrades (interconnects, power cords, and most especially tubes), the sound (and music) is remarkable. If you go with Jolida, make sure you get a late model unit with the standard factory upgrades (last year or so). |
If the 86db/1W/1m sensitivity figure is accurate, it can be calculated that a 60W amp such as the Jolida 502 can provide a maximum spl of 99db at an 8 foot listening distance, neglecting room reflections. A 100W amp would provide 101db.
I second the concerns Grant (Tvad) expressed that if the speaker's impedance curve is significantly uneven (which I suspect is likely, based on the driver configuration), tonal balance problems would result with a tube amp. I did a quick search, but could not find an impedance curve for any of the Fritz speakers. I second the suggestion of contacting Fritz.
Regards,
-- Al
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i appreciate all the comments. lots of different opinions here. i will contact fritz about his thoughts and report back. |
It seems like Tvad and Al and others are backing up my concerns here, though I personally would try to solve the issue from the other direction, in other words go for high efficiency speakers instead of more amp power. But I am also of the mind that the speakers are by far the most important part of the system, so if you like those speakers, then it sounds like you should go for a higher powered amp. If you don't like the sound of your speakers, you won't like the sound of anything else in your system. |
my fritz groves are one of the best speakers i have heard under $4000. i dont see myself ever getting rid of them unless i hit the lottery. |
You could pick up an Onix Sp3 for about $500, that should give you a good low cost intro to tubes. If you don't like it or want more power you can resell it for about the same price you paid for it. |
What did the manufacturer recommend for using tubes for amplification? |
If the amplifier has an output impedance that is low enough, you can have variations in impedance that will not result in tonality issues with most tube amps, as long as the variations are not extreme. For example, a 4 ohm dip at a crossover frequency can be considered benign.
A lot has to do with the intention of the designer of the speaker- if the speaker is designed to be friendly to tubes, that is usually more important than the actual impedances. |
spoke with Fritz and tubes are a definite go! |
11-16-10: Rayray8
spoke with Fritz and tubes are a definite go! What did he say was the minimum impedance of the Grove speakers? |
tvad, its an 8 ohm speaker and im sure it dips lower at different frequencies but most tube amps including the one i ordered have 4 and 8 ohm taps. all i have to do is try each output and decide on which i like. |
Rayray8, you're missing the point that was made earlier about minimum impedance. I am well aware of tube amps that have 4 and 8 ohm taps. I've owned several myself.
I have also owned 8 ohm nominal speakers that didn't sound correct on either tap due to the impedance dip, and this despite the well respected manufacturer claiming the speakers were "tube friendly".
It's always a little baffling to me when speaker builders don't specify the minimum impedance of their product and rather just tell the owner that it'll be no problem driving them with a tube amp.
Enjoy the journey. It's half the fun. |
all i know is that others are using his speakers with tubes with no issues. |
Rayray8, hopefully you'll be ecstatic with the tube amp.
*If* the sound is a little bass shy, or *if* the speakers sound too bright, then I would suggest you look first to the amp/speaker match before you start to fiddle with anything else...like wire, source, power, etc. |
"all i know is that others are using his speakers with tubes with no issues."
With all due respect Rayray8, if you're going to use that as the main criteria on which you base decisions, IMO, you're going to be in for a rough time of it.
Tvad is not being pedantic, he's trying to teach you something. The title of your thread is"new to tubes". There's a science to speaker/amp pairings that, while you're certainly free to ignore in lieu of whatever methodology you choose, you would be wise to at least understand before adhering to subjective opinion. Just my two cents worth. |
i fully understand what you are talking about. bottom line is i spoke with fritz who has used tubes with the speakers and recommended me several amps in my price range that he actually has. i also know there are others who use tubes with these speakers and all is well. i'd rather take the advice of the speaker builder and of those that actually have these speakers then that of people just speculating. i appreciate the opinions and yes, i am learning and new to tubes, so im sure there might be some trial and error associated. |
If you do some research, e.g. reading something like Robert Harley's "The Complete Guide to High End Audio" (especially the chapter about amplification), then there will be no trial and error (nor speculation) regarding proper speaker/amplifier matching.
FWIW. |
i spoke with fritz who has used tubes with the speakers and recommended me several amps in my price range that he actually has.
Rayray8 (Threads | Answers | This Thread) Specifically, which tube amps did Fritz recommend? It'd be helpful to have this posted for future owners to research in these threads. |
Tvad that was the reason for asking my earlier question as well;it would be very helpful to have the the information of what the maker said would be a match for his speakers and which are not. |
I know I'm chiming in on a 3 month old thread. I assume RayRay8 has his amp and all is well, but for what its worth. I've built with the same woofer on the Fritz Grove. It is also the same driver used in the Totem Forest. It does not have any crazy impedance dips, and the real question is phase angles. This woofer does occasionally go reactive in phase angles, but overall is a capacitive load. MOST, not all tube amps will drive this speaker fine as long as you have enough power. Also RayRay8, This woofer really takes along time to break in, I would recommend to not take anything that you hear to heart until you have 200 hours on them. They will still get better up to 300 hours, but at 200, you'll have a good idea.
Good Listening, Tim |
