Hey gang. I have a Hafler DH500 with one dead channel, at least that is what my note says. I will need to dig it out of my storage trailer and have a look.
I really have no use for yet another high power amp. I am trying to lighten the load.
If anyone is interested in it, let me know.
I really have no use for yet another high power amp. I am trying to lighten the load.
If anyone is interested in it, let me know.
Hello guys a build the the bod Cordell board I for my dh-500 install everything just following you guidance but now I’m getting DC voltage on speaker terminal can any one please 🙏 give me some advice
I had one case reported of a similar issue, it was the dc servo opamp has a folded lead not making contact in the dip-8 socket.
Thanks guys I found it I may have rush the work on the las minutes I have place q17 to the opposite direction it’s working beautiful now
Care to inform us on the sound compared to stock. I've yet to work on mine and I'm just wondering how it'll be. Thanks.
The sound it’s way better then the stock the 3D imaging is better I can hear things I have never heard before and my speaker sound better than I can never imagine you have to get done you won’t be disappointed
I am looking at using the DH200C circuit boards in a Dynaco Stereo 400 rebuild. The mechanical fit looks tight but ok. I have 2 concerns I would appreciate comments on:
1. For one channel, the wiring length from the AFE and OPS for one channel will be rather long, estimate is 12 inches (300 mm), then another 3 inches to transistors.
2. The Dynaco heatsinks are prepared for 2 pair of output transistors. Is this enough for amplifier with +/-74 VDC rails? (I hope so, that is all the matched Exicon TO-3 transistors I have).
I have been using DH500C and like it a lot, so I hope similar upgrade to the Dyna 400 will work out.
1. For one channel, the wiring length from the AFE and OPS for one channel will be rather long, estimate is 12 inches (300 mm), then another 3 inches to transistors.
2. The Dynaco heatsinks are prepared for 2 pair of output transistors. Is this enough for amplifier with +/-74 VDC rails? (I hope so, that is all the matched Exicon TO-3 transistors I have).
I have been using DH500C and like it a lot, so I hope similar upgrade to the Dyna 400 will work out.
Glad hear your feedback on the DH-500c design.
I took a quick look at that Dynaco design. It specifies two complementary pairs of 200w bjt output devices.
Single die exicons are rated at 125w and dual dies at 250w so dual die devices would be the preferred devices for that supply V imo.
As far as wiring length goes, it’s something that needs to be tested out for oscillations and stability.
No easy answer as far as a simple yes or no since you are deviating from the intended application of the original design.
I took a quick look at that Dynaco design. It specifies two complementary pairs of 200w bjt output devices.
Single die exicons are rated at 125w and dual dies at 250w so dual die devices would be the preferred devices for that supply V imo.
As far as wiring length goes, it’s something that needs to be tested out for oscillations and stability.
No easy answer as far as a simple yes or no since you are deviating from the intended application of the original design.
Thank you for comments re. using DH200C in a Dynaco 400 rebuild. Using the dual die Exicon is a good recommendation, so I have gone ahead and ordered some. Profusion has very limited stock left on these.
I understand I am taking my chances with the new application. Closer inspection of the Dynaco shows the OPS may not fit - I may have to lay out a narrow OPS circuit board. Should be fun.
I understand I am taking my chances with the new application. Closer inspection of the Dynaco shows the OPS may not fit - I may have to lay out a narrow OPS circuit board. Should be fun.