Amp for Dahlquist DQ-10


I have recently discovered this site and appreciate the opportunity to learn about audio from the knowledgable people the participate in this forum.

I have a pair of DQ-10's that I bought new in the late 70's. They always seemed under powered by my Hafler DH-200, but still sounded great. I'm using a Crown IC-150 pre-amp.

I recently purchased an Adcon 555 power amp. That seemed to perk the DQ's up quite a bit and with it my interest in refreshing my system. I'm now considering either replacing the Crown preamp or adding a second Adcom 555 power amp, but I'm not sure which change will give me the most bang for the buck. If the replacement of the preamp is the best route, I'm interested in hearing suggestions of which preamps will mate well with the 555.

Since I will likely be buying used equipment online and won't be able to listen before I buy, I wanted to see if anyone here was willing to offer a suggestion.
laffer
I haven't sat in front of DQ 10's in a long long time, but I have sat in front of them in a couple of homes probably 25+ years ago and once in my store. I modded the pair in my store. In the store we put them on Sumo gear, it did a good job on them, the nine was warm and inviting, but in the homes, one was much better, He used a Audio Research Preamp and Kenwood LO7M power amps. This was a very nice combination indeed. I would today, still recommend a tubed preamp that is warm and rich, along with a power amp that is fast and accurate. These old speakers would sing again. Everyone won't like that Adcom amp, but it is alot of bang for the buck, If you like it, run with it. I might recommend a Joule-Electra Preamp. Maybe a Conrad Johnson... Depends on Budget. Good Listening, Tim
My sister still has her DQ-10's from back in the day - and now she has her Mac electronics back and driving them, just like when she first got that gear. That combination has always worked for me (but then you're reading comments from someone who drove speakers w/ a DH-500 for years). I'd guess you could find a second 555 for a price that makes that approach very reasonable (and if that doesn't do what you'd hoped you could sell that 555 for approx. what you pay and then try the pre-amp route). You know you liked that combination - so now you just want a bit more of it.
Thanks for your comments. The pre-amp upgrade seems to make a lot of sense. I've often admired the sound but never developed the knowledge to be confident in this area. I'll research Timlub's recommendation on tube pre-amps. Adding a second 555 is pretty simple and inexpensive, so I can address that later. I'm guessing that the pre-amp will make a more significant improvement than adding power. I like music at high levels, but one 555 is pretty strong by itself.
Any thoughts on the GFP 565 vs the GFP 750? Cost seems to be about $300 vs $750. I'd want to consider spending the extra $ if it was a significant improvement.

I did see a CJ PF1 in the $4-500 range, but I'm concerned that an older tube pre amp might require more attention than I want to give it (not sure how long tubes last or how tempermental it might be). Is my concern overblown?
The GFP565 is known to be Adcom's best standard line product, however the GFP750 is not their standard line product, it was contracted by Nelson Pass, there are a ton of threads and arguments about it here on Audiogon, but any way you look at it, it is in another league, better than the GFP565.
I ran mine with a pair of "bridged" CITATION 16a's to a very nice result. I had a stacked double pair of Mirror Imaged DQ-10's.

The soundstage was stunning!!
I've listened to several pair of DQ-10s with various electronics; in general you can't go too far wrong with any good amp or preamp, or even a good receiver. At the low end you would be surprised how good they can sound with a Marantz 2230, 2245, or 2270 receiver (assuming the receiver has the original parts and they are operating properly). For still better sound, go with a tube amp and preamp. An Audio Research D76A amp with an Audio Research SP3A1 might blow you away with open airy detailed highly imaged sound. Other good tube equipment would probably provide a similar effect. The more power you can deliver the happier the DQ-10s will be - they like power. So you probably want 70 to 200 watts per channel if can afford it - but even around 70 watts you can get the job done. I think if you replace that Crown pre-amp you might be surprised with what else the DQ-10s can reveal in the way of pleasant sound. Keep working on your electronics - the DQ-10s are almost impossible to beat for the price they go for on the used market. Let us know what you wind up doing.

Thanks for the feedback. Based on what I've learned from this thread, and some additional research, I'm currently leaning toward adding a GFP 750. It looks like I'll have to spend $600 - $800 if I go this route, but it'll be worth it. While the Crown preamp has been a great and reliable component, it appears to be the weak link in the systemat this time.
Hi Laffer,
I recommend that you do everything that you can to audition Adcom gear with your DQ10's. We have all learned the hard way that all of our ears are different, but for me, there is no question that I would develop fatigue fairly quickly with Adcom and Dahlquist. DQ-10's are detailed, revealing and without mods a touch light on the bass, DQ-10's will get edgey with some equipment.
Now after all of that said, If you like the Crown/Adcom combination, forget all the above. The GFP-750 will lunch it in every aspect. Good Listening, Tim
I am running DQ-10s with the LP1 and 2 DQ subwoofers. The subs made a big difference, taking the load off the woofers reduced the distortion quite a bit.

I have used solid state, tube amps and hybrid amps with the 10's as satellite speakers, and they seem to like the tubes the best.
I've thought that going the subwoofer route would be appealing with the DQ-10s. That way I could avoid the second 555.

Do you think that the Dahlquist subs are key, or would another quality sub do the job?
You could go with another sub but the LP-1 is essential. I had mine recapped and uprgraded op-amps as well. I use only one W-1 bass module. I also had my DQ-10 recapped by Regnar and power them with a pair of Luxman MB-3045s. I have a McIntosh MX-110 pre-amp/tuner which was modded by Richard Modafferi so you can see I have invested a lot in to this system.