Decky Posted July 3, 2011 Posted July 3, 2011 (edited) Item:Holton Precision Audio HPA-LSP400se monoblocks + CAT5 speaker cable Location:Canberra Price: SOLD Item Condition: Used - Excellent Reason for selling: Surplus of amps Payment Method: Money transfer, Pickup - Cash Extra Info: I offer for sale a DIY implementation of Anthony Holton's LSP400 mosfet amp modules. Close to 300W/pc in 4ohms with both balanced and single ended inputs. More info and a review here: http://www.aussieamplifiers.com/nx400nl.htm http://www.tnt-audio.com/ampli/aussie_amplifiers_lsp400_e.html My implementation started by packing two transformers and soft-start circuits in a separate steel box while PSUs, rectifiers and amp boards are housed in modified Lian Li AL computer cases. Cases have extra inner lining of aluminium and copper for better shielding. Input capacitors are Solen PP. Connectors are Vampire copper for SE, Neutrik for XLR and Eichmann for binding posts. All wiring is silver plated copper in teflon. The signal output wiring is Van-den Hul. PSU caps are Panasonic rated at 100V and there is 54400 uF of capacitance per monoblock. To sweeten the deal I will drop in for free a CAT 5 (Belden 1585A based) speaker cable, dressed and terminated with Vampire copper spades and Eichmann banana plugs. Length 2.5m. Pictures: Edited July 24, 2011 by Decky
petng Posted July 4, 2011 Posted July 4, 2011 Hi Decky. I notice that there are left and right RCA's on each amp, does that mean they can be configured for horizontal biamping? Also what is the output at 8ohms? Thanks
petng Posted July 4, 2011 Posted July 4, 2011 Decky, the specs on what i could find shows 200w per chanel. Are your amps made with 2 boards? If so they should be outputting more watts than in stereo mode.
Decky Posted July 4, 2011 Author Posted July 4, 2011 Two RCAs are there for bypassing not for biamping. I used them for a while in a 2+1 configuration - bookshelves and a sub. That is the purpose of two RCAs. Regarding the power - amp modules are designed for maximum DC rail voltage of 74V which from memory gives around 380W in 4 ohms (Anthony can correct me on this if I am wrong). Hence, the real output power is only defined by the transformer secondaries. My transformers give 66VDC rails so projected power is closer to 350W in 4 ohms. I deliberately put 100V rated capacitors in the PSU so one can push the amp to the maximum by replacing transformers and pulling almost 400W per side. However, I never used more than 20W of power from them anyway.
hedalfa Posted July 4, 2011 Posted July 4, 2011 (edited) I got the chance to demo these amps in my system. I can verify a couple of things. There is amble power here. My existing haffler DH500 amp is rated at 250 watts per channel. Deckies amp at least in my system behaved like it had more power than the haffler. Great dynamics, speed and clarity. They just didnt synergise in my system otherwise I would have bought them myself. (I have a multi amp system). Its also nice touch that they have good binding posts and rcas! Would be well suited to a system that needs a bit of horsepower to make the speakers work. Edited July 5, 2011 by hedalfa
Decky Posted July 23, 2011 Author Posted July 23, 2011 Back on the market. Rechecked and re-biased and with an adjusted price ....
Guest Posted July 23, 2011 Posted July 23, 2011 Hmmm.... wonder how these would cope with difficult speakers....
Decky Posted July 23, 2011 Author Posted July 23, 2011 I built them with intention of pairing them with electrostatics. Was thinking to invest in Martin Logans but SGR happened and the plan was no more. I do not have anything so difficult to try them with now, but they should give plenty of grunt to any speaker known to man. They are designed to be 2 ohm friendly. How difficult we are talking about?
Guest Posted July 23, 2011 Posted July 23, 2011 I built them with intention of pairing them with electrostatics. Was thinking to invest in Martin Logans but SGR happened and the plan was no more. I do not have anything so difficult to try them with now, but they should give plenty of grunt to any speaker known to man. They are designed to be 2 ohm friendly. How difficult we are talking about? Looking to push some serious current into my Gale 401s.
Decky Posted July 23, 2011 Author Posted July 23, 2011 Tough bastards.... Well, as far as I see the impedance does not drop below 3.5ohms. It would all depend on the SPLs you want to achieve. My bookshelves are ~86dB sensitive with constant impedance of 3.8ohms between 200Hz and 20kHz but I do not use more than 10W in my 3x3 room. Consequently amps are hardly above the ambient temperature. I would not say that they will sweat too hard with Gales.
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