Speakers

[gogzhad]

Ditto the recommendations for A-25's - get an original series set and I don't think you'll be disappointed, plus, if you get a set in good condition, the cabinets are pretty attractive. These work very well with ST35's and ST-70's, even Mk III's. You can find them easily on eBay, but hard to verify if they're early or not.
Another great pair, though generally not as economical, is the Klipsch Heresy - very efficient and very good sound, though some complain the horn mids tend to ring.
Either way, your little ST35 will shine.

[mesherm]

My apartment is space limited so I purchased a pair of JBL Northridge E50 bookshelf speakers. They sound pretty good and they are 90db sensitivity. They seem to be a bit boomy on the low end with SS amps but sound good with my ST35 clone and my other tube amps. I just don't have room for anything bigger until I can afford to trade in a huge Sony picture tube HDTV for a plasma or LCD screen TV...which will probably be the day after I hit the lottery.

[DerekVa]

I'm running a pair of Axiom Audio M22ti speakers (95db 1W/m) with a Hsu STF-2 subwoofer with my more-or-less stock (albeit with a beefier power supply and better components in the signal path) ST35. I can drive people out of the room with this setup without having to resort to music that features yodling.

-Derek

[erichayes]

Found it

[cfranz]

Interesting new speaker - looks like the Dynaco A-25's with new drivers and crossover parts. Not sure if they are available in the US. Anyone tried these?

Regards,

They are based off the A-25s, author says so. Personally, I'm willing to give them a whirl... as soon as I can't find A-25's for $120 on EBay no more.

[wiredbecker]

I just picked up a pair of A-25 XLs and I'm really enjoying them with one of Tom's 3/4 watt Darling amps.

Hey WA4SWJ,

Did you ever figure out if those were Advent tweets modified to fit the A-25s? I have a pair of the stock original Advents handy, I could pull the tweeters and take detailed photos if you'd like to compare drivers.

[WA4SWJ]

Howdy Wired,

No, I never did look at them in any more detail. However, I have seen some Dynaco A-25's on eBay that had the same tweeters. They seem to be rare though. The tweeters have yellow-orange domes and they are marked "MT160-3'. I don't see any other markings other than "Inspected by" type marks. There are no manufacturer's marks at all. I replaced them with some Morel MDT-20's and that improved the speakers in my opinion. However, when making a change like this it would be a good thing to measure them and determine if a crossover change is warranted to make sure the response is as it should be over the spectrum. I did not do that because I do not have the equipment. I'm happy with them though.

I can send some pictures of my tweeters if you're interested.

[wiredbecker]

Thanks Ed.

It's not a big deal really.. you gave a enough info in your post. One of these days I'll get around to checking. Hell, I should hook up those Advents and see how they sound with this tiny amp.

oh yeah, my name is Chris Becker. Pleased to meet ya

[erichayes]

Here's another.

[EdStiles]

I'm using a pair of Klipsch Fortes with a modified ST-35 and an ARC SP3 (lastest factory mods) preamp and it sounds great. Music is mostly jazz, some rock, these speaker get loud and deep. My ST-35 is the orginal Dyna version with a C Chong power supply board, Dyna C354 choke and replacement boards using premium parts.

The Fortes are modified with Auricaps replacing the original 1 and 1.5 mfd caps, the 47mfd electrolytic was replaced with a Solen Fast Cap. The horns and the woofer frames were damped with Dynamat Extreme to minimize vibrations. The end result is a very good sounding speaker that does an accurate job of reproducing sound.

The other day, had a couple of young guys come over, they were local studio guys selling me a 24/96 digital sampling board for my PC; I intend to use it for converting some of my older vinyl to CD. While their choices in music were probably different from mine, they expressed amasement over the accuary of the sound coming out of my system, then truely flipped when I told then that a grand total of 17 watts/channel was driving this sound.

DIY can take a good product that was limited by cost considerations or older technology and make it great; a little research and some time slinging solder can get you something you can be really enjoy.

[thspeakerdude88]

Since this thread was already here I thought I would mention my question.

I've got sansui SP-1500's that I am planning on driving with the st35. I don't know how accurate the factory DB rating was, but it says they are 98db in the owners manual. Sureley they cant be talking about the WHOLE system, I can't imagine the woofers being that sensative. Anyways I am running them off an onkyo TX-1500, which has STK075 outputs. Data sheet says 15 watts @.5%THD on +/- 22v rails, and my rails are just about +/- 24v. Amp really lights up the sansui's and drives them to way more volume than I need. With the powe ratings being so close, will the ST35 actually have more power? Whats the maximum output before noticing clipping distortion on a 35?

[erichayes]

Most tube amps do a thing called "soft" clipping, which allows the ear to tolerate more distortion than test instruments say it should, compared to a solid state amp of equal power. You hear people talking about how tube amps sound twice as loud as comparable SS amps, but it's all a matter of tolerable distortion.

Hope that helps.

[Ty_Bower]

With the power ratings being so close, will the ST35 actually have more power? Whats the maximum output before noticing clipping distortion on a 35?

I think it depends somewhat on your output transformers, the condition of your output tubes, the plate voltage and idle current, and how closely you've matched the bias in each output pair. I'd guess of these the transformer choice has the biggest impact. I used Hammond 1620 outputs on mine because they were very inexpensive. I'd be happy to use them again - I think they sound great. I put my ST35 on the 'scope. Here's some of my results:
http://www.diytube.com/phpBB2/viewtopic.php?t=1680

I found that for 20 Hz sine waves, I might hope to get a little over 4 watts before it starts to break up. I don't think this is a fair test. The 1620 isn't rated down that low, and my speakers don't produce any useful output at the frequency. At a more reasonable frequency, it's good for at least three times the watts. My "listening room" is good sized, maybe 30'x15'x8'. I run my ST35 into a set of Paradigm 7se MkIII speakers. It plays plenty loud and clean for my tastes, with a rich solid bottom end.

[EWBrown]

Some of those 1970s vintage Japanese speakers had very high SPLs.

I used to think that they sounded pretty bad, but then that was when they were connected to early 1970s SS receivers amps (which did sound pretty bad).

Put these on tube amps, and they really come into a league of their own.

A lot of these speaker systems had some pretty elaborate and complex 4 and 5 way driver arrangements, and perhaps some crossover mods should improve their sound (at least replace the non-polarized electrolytic coupling caps with Solens or Dayton MKPs).

One overlooked brand (I had four of them while over in Viet Nam,and Isold them before I left) is "Coral" speakers, These were 8 inch, 2-ways and reportedly are very good "tube-friendly" speakers.

On a Sansui 5000X, they sounded "mediocre" at best, but then that was the amp's fault, not the speakers'... That Sansui 5000X made every speaker I ever tried on it sound bad. Yellow_Light_Colorz_PDT_21 Yellow_Light_Colorz_PDT_21

OK, I digress a bit...

After the 5000X power amps blew out (they always did, even with the "super-special mil-spec mods") I used it as a tuner / preamp for a while, before consigning it to the freebie table at a hamfest... The mods for the 5000X entailed replacing the TO-3 power transistors and their driver tranistors, with some nice mil-spec devices courtesy of Uncle Sam - I worked in a repair depot over there, and it was like working in an experimenter's candy store...

Those power amps were all direct-coupled, and before the days of complimentary pairs, so the outputs were coupled through some big fat electrolytic caps, which was the main cause of their atrocious sound quality. If one transistor went bad, it was like a string of firecrackers, they ALL went bad...

/ed B in NH

[K-MAN]

I'm using Kenwood 3 way speakers which are pretty large but I replaced the caps in it and stuffed the cabinet with some pillow stuffing and that made a big difference in the sound quality. I feel good speaker wire and connections are really important too since you don't want to lose any more power than you have too with these small amps.