Ol_mcdonald Posted October 10, 2020 Share Posted October 10, 2020 Just gauging opinions on using a vintage Crown D-75A to drive the top end of bi amped Klipschorns. I have access to one I can purchase cheap enough to have it gone through and upgraded as necessary as I know it has some age, but then so do I! Thanks in advance for your input. Opinions have varied wildly (as I expected) in other forums. I anticipate more rational responses here! Quote Link to comment Share on other sites More sharing options...
OO1 Posted October 10, 2020 Share Posted October 10, 2020 22 hours ago, Ol_mcdonald said: Just gauging opinions on using a vintage Crown D-75A to drive the top end of bi amped Klipschorns. should work ok --if newer premium parts are added -it should be even better , but all original is ok too Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted October 10, 2020 Moderators Share Posted October 10, 2020 Yes try it, I used 2 of them on a more sensitive horn setup and had no noise of any kind. They played clear and clean, it was way better than expected. After years one developed a hum, NOT in the speaker but from the amp itself so I switched both out. But I really liked them and if rebuilt like the one they call the Duke in some thread around here it would be even better. I used one for the 2 horns and one for bass bins, bi amped and active crossover, I really liked them, bought them as a pair from ebay and surely got my money's worth in years. 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted October 11, 2020 Share Posted October 11, 2020 Would be interesting take one and only do the power supply and coupling cap upgrades and see how far that gets you. I have the modded D-45 (the Duke), and it is very, very good. Dead silent. It also has some resistors changed to up the input impedance so tube preamps can more easily drive it. More was done, ... I use a tube line stage, and have no gain issues or bass rolloff problems. Are you using a digital crossover to time align the drivers? If not, John Warren has a crossover board that fits inside a D-75, so you can use one D-75 per cabinet. 1 Quote Link to comment Share on other sites More sharing options...
Ol_mcdonald Posted October 11, 2020 Author Share Posted October 11, 2020 Yes, I am using a dbx Driverack PA2. Entire setup is solid state. dtel also mentioned the Duke and I am interested in more info. I would like to use this amp and have interest in upgrading it before it is deployed. Thanks for your input. 1 Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted October 11, 2020 Share Posted October 11, 2020 A pair of klipschorns deserves better than a Crown amp. 1 Quote Link to comment Share on other sites More sharing options...
Chris A Posted October 11, 2020 Share Posted October 11, 2020 21 hours ago, Ol_mcdonald said: Just gauging opinions on using a vintage Crown D-75A to drive the top end of bi amped Klipschorns...Opinions have varied wildly (as I expected) in other forums. I anticipate more rational responses here! I use D-75As on all surround bi-amp/tri-amp channels except the left/right compression drivers. The difference in sound quality with a higher priced amplifier is quite small--small enough that most people would not be able to pick it out in a blind test on the TAD TD-4002 compression drivers, I've found (everything dialed in properly). I'm not always able to identify the difference, and I listen to the setup at least a couple thousand hours per year. And the "Duke" upgrade removes any remaining differences. You'll do very well with a D-75A on the top end. https://community.klipsch.com/index.php?/profile/26262-chris-a/&tab=field_core_pfield_14 Chris 2 Quote Link to comment Share on other sites More sharing options...
tromprof Posted October 11, 2020 Share Posted October 11, 2020 I use several Crown amps in my all horn home theater They do as great job. I also have a D-75A currently in my Klipschorn system. Again, a great sounding amp. Like many companies Crown makes a wide variety/quality of products. The D-75A is a good one. Don't let snotty generalized comments stop you from trying one. 3 Quote Link to comment Share on other sites More sharing options...
Marvel Posted October 11, 2020 Share Posted October 11, 2020 2 hours ago, Ol_mcdonald said: I would like to use this amp and have interest in upgrading it before it is deployed. Mark Deneen, owner/designer (now retired) of Juicy Music Audio, modified a Crown D-45, and named it "The Duke", after one of this forums former members. He replaced about eight or so parts, two op amps, resistors and capacitors. He said his aim was to increase the input impedance (for the benefit of tube preamps higher output impedance), to increase the slew rate (may or may not actually be beneficial), and get a smoother sound, all while keeping it robust and trouble free. I think the D-75 models changed to using surface mount parts for most of the board, not really sure, but the two sections that would probably be the most benificial would be the power supply caps and the coupling caps. You could contact John Warren at North Reading Engineering as he made some crossover boards for the D-45/75 series and could probably do the work. Since you are using a DriveRack, you wouldn't need the crossover boards. https://www.northreadingeng.com/ @John Warren Bruce 3 Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted October 11, 2020 Share Posted October 11, 2020 2 hours ago, tromprof said: I use several Crown amps in my all horn home theater They do as great job. I also have a D-75A currently in my Klipschorn system. Again, a great sounding amp. Like many companies Crown makes a wide variety/quality of products. The D-75A is a good one. Don't let snotty generalized comments stop you from trying one. To each his own. It's ok if we have different standards for sound quality. It won't end the world as we know it....... 1 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted October 12, 2020 Share Posted October 12, 2020 7 hours ago, Shakeydeal said: A pair of klipschorns deserves better than a Crown amp. I would not have expected the Duke to best my 2A3 amps on my LS, but it does. And for all those who have heard my Moondogs, that is saying a lot. Better amps? I'm sure there are. Less expensive? Getting a lot harder. Now, I would like to find another D-45 and try doing Mark's mods myself. 3 Quote Link to comment Share on other sites More sharing options...
babadono Posted October 12, 2020 Share Posted October 12, 2020 Go Bruce Go Quote Link to comment Share on other sites More sharing options...
artto Posted October 18, 2020 Share Posted October 18, 2020 Crown D75 should work fine. IMO not the best choice for driving the top end of Khorns. All of the Crown D series are similar circuitry. The main “sound” problem with them is the op-amp integrated circuits they used. Not exactly what most people would call the smoothest or “nicest” sounding top end. That being said I still have a couple of Crown D60 and D150A. I’ve used them full range on the Khorns and Belle center speaker. FWIW the Crown PSA-2 I had was one of the better sounding Crown amps I’ve used – sold it because the internal fan had to be on all the time – too much noise for my room. Crown K2 are nice too. Overall I’d have to say (IMHO) that any Crown amp being used in a bi-amp configuration, especially with horns, is best suited to for the bass, not the midrange/treble. I also agree with Marvel (Bruce) about Mark Deneen’s modifications on the Crown D45. 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted October 31, 2020 Share Posted October 31, 2020 On 10/11/2020 at 9:03 PM, Marvel said: I would not have expected the Duke to best my 2A3 amps on my LS, but it does. And for all those who have heard my Moondogs, that is saying a lot. Better amps? I'm sure there are. Less expensive? Getting a lot harder. Now, I would like to find another D-45 and try doing Mark's mods myself. the overall Deneen upgrade are easy to do , there is 1 part however , and I would have to re-look at the list of the modifications that requires a lot of attention and skill as far as soldering ---- Quote Link to comment Share on other sites More sharing options...
Marvel Posted November 1, 2020 Share Posted November 1, 2020 15 hours ago, RandyH000 said: the overall Deneen upgrade are easy to do , there is 1 part however , and I would have to re-look at the list of the modifications that requires a lot of attention and skill as far as soldering ---- I don't think any of the parts are difficult to solder. The 14 pin parts aren't fun to get out, but they are easy if you don't want to save them. You cut all the pins so you can desolder them one at a time. A vacuum desoldering tool would make it easy, but I haven't had access to one for 20+ years. Quote Link to comment Share on other sites More sharing options...
OO1 Posted November 1, 2020 Share Posted November 1, 2020 3 minutes ago, Marvel said: I don't think any of the parts are difficult to solder. The 14 pin parts aren't fun to get out, yes , these ones -I have staff that are very good with a Soldering iron , but these guys hate working on old stuff ---SMH Quote Link to comment Share on other sites More sharing options...
Marvel Posted November 1, 2020 Share Posted November 1, 2020 I used a desoldering pump... had a hollow tip you placed over the tip of a part, pushed button and it sucked the slder clear out of the hole. The vacuum pump had a little container the held the molten sold. Wish I had got it when they closed the company. Quote Link to comment Share on other sites More sharing options...
billybob Posted November 1, 2020 Share Posted November 1, 2020 Solder sucker... Some still around by diff. brands. Here... https://www.ama... Quote Link to comment Share on other sites More sharing options...
Chris A Posted November 3, 2020 Share Posted November 3, 2020 This one works pretty well: https://smile.amazon.com/gp/product/B002MJMXD4/ The price went up $5 since I bought mine. Chris 1 Quote Link to comment Share on other sites More sharing options...
Blvdre Posted November 3, 2020 Share Posted November 3, 2020 I have an old Pace desoldering station, which was useful for replacing through-hole PCB parts, but I haven't used it in ages. I use the Soldapullt instead. I've been using the same sucker for over 30 years, and it stills works like a champ. If you get some spare tips and O-rings, it'll last a lifetime 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.