i have never had any tube equipment and am thinking about trying it out. i am learning slowly about it and thinking about taking a leap with a lower priced piece. i currently have a Cambridge Audio 840v2 integrated amp and a pair of Fritz Grove monitors. my only source is a Squeezebox Touch. i already plan to get an Eastern Electric Dac. my only concern is how much power is enough to drive the groves as they are only 86db efficient. my room is only 13'x 11' treated,and i dont listen past 92 db. i'm thinking on the lines of a Jolida 502b to start. trying to stay under $1000 used. any thoughts?
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.
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.
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...
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.
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.
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.
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.
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.
"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.
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
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