BlackGTS Posted January 3, 2014 Share Posted January 3, 2014 This question will expose my lack of knowledge in the audiophile world, but here goes: I can pick up a QSC ISA 300T for $100 and use if temporarily until I can find the right Acurus or Parasound amp. I will use it behind my RF-83s in a 2 channel setup for music. I know that pro amps aren't really the ideal amp for what I want., Fan noise isn't going to be an issue and I know that the connection to and from the amp isn't optimal. Can this amp safely be used for these speakers? Can the connections be modified for this application? Is it worth the hassle or a downright bad idea? Feel free to bash away. Ron Quote Link to comment Share on other sites More sharing options...
Shodrewken Posted January 3, 2014 Share Posted January 3, 2014 I have an Acurus A150 I might consider selling. Quote Link to comment Share on other sites More sharing options...
BlackGTS Posted January 3, 2014 Author Share Posted January 3, 2014 I have an Acurus A150 I might consider selling. Thanks. When I do decide to buy a nicer amp I want to get one that I can run all 5 HT channels at about 200 each channel. But...... PM sent. Ron Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted January 3, 2014 Share Posted January 3, 2014 You didn't ask, but your comment just seemed strange.. so I'm providing unrequested feedback. Your RS-42's are not power hogs. the content sent to surround channels is ancillary and not the bulk of a movie's core audio content. Sending 200w of really expensive amp power to those two channels is a huge waste of power and money. Let your Denon run those two channels and offload the really important stuff from the front stage to a nice 3-channel amp. You wont have to spend as much, you won't have to wait as long, and you won't be wasting two channels of power. Just something to think about. Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted January 3, 2014 Share Posted January 3, 2014 You can always get RCA to XLR or RCA to 1/4" adapters if you need to. Most pro amps will allow the connection of regular speaker wire although some will only have speakon connections and I'm not sure how you'd go about connecting a speaker with speakon on one end and bare wire on the other end. Monoprice will have any and all adapters you'll need. Quote Link to comment Share on other sites More sharing options...
BlackGTS Posted January 3, 2014 Author Share Posted January 3, 2014 You didn't ask, but your comment just seemed strange.. so I'm providing unrequested feedback. Your RS-42's are not power hogs. the content sent to surround channels is ancillary and not the bulk of a movie's core audio content. Sending 200w of really expensive amp power to those two channels is a huge waste of power and money. Let your Denon run those two channels and offload the really important stuff from the front stage to a nice 3-channel amp. You wont have to spend as much, you won't have to wait as long, and you won't be wasting two channels of power. Just something to think about. No. ALL feedback is requested This is kinda what I am dealing with now. I don't have my HT yet, so no need to buy the 3 channel just yet. I am pretty set on an Acurus or a Parasound when that time comes. Until then, the Denon just isn't cutting it for the 83's. I would like to really enjoy them (translation, turn them up loud) occasionally until they go into the HT. I'm just not feeling the love right now and it is probably because of a lack of headroom, I don't know. What I do know is that I have had these 83's for over a month now and would really like to take them for a spin. For now, $100 would be well worth it if I could make it work. Any and all feedback or opinions are greatly appreciated. Ron Quote Link to comment Share on other sites More sharing options...
BlackGTS Posted January 3, 2014 Author Share Posted January 3, 2014 This is the info on this amp: Designed as a cost-effective solution specifically for sound contractors, the ISA Series features seven models including four low impedance models (ISA 280, ISA 450, ISA 750) rated for 2-ohm operation, and three "Ti" versions with isolated 25, 70 and 100 volt outputs for distributed audio systems (ISA 300Ti, ISA 500Ti, ISA 800Ti). Versatile loading options and a comprehensive feature set make the ISA Series a rugged, cost-effective power solution for any permanently installed sound system. Unique among distributed sound power amplifiers, the "Ti" versions will drive 8- or 4-ohm loads and a distributed system on the same channel simultaneously. This enables a contractor to reduce the number of required amplifier channels by allowing a limited number of distributed speakers to be attached to the same amp as is powering the main sound system. Housed in a rugged 3-U chassis, all seven models feature rear panel gain controls for tamper resistant operation with 2 dB detents for quick and repeatable settings. Inputs include both XLR and detachable Euro-style connectors. Outputs feature covered barrier strip connectors for safety agency compliance, and for added versatility, a DataPort V2 (Version 2) terminated with an HD-15 connector is provided for use with DPV2-compatible signal processing accessories such as the XC-3 Crossover, SF-3 Subwoofer Filter, LF-3 Low Frequency Filter and the DSP-3 with external power supply. Selectable high-pass filters are included to protect speakers and prevent speaker transformer saturation with minimal effect on program material. The ISA Series provide additional protection circuitry including DC, infrasonic, thermal overload, RF and short circuit protection. On the ISA 750 and ISA 800Ti, class H complementary bipolar output circuitry increases system efficiency by reducing AC power draw and waste heat by 40%. Cooling is accomplished via an automatic variable speed fan, which pulls air from back to front. Features: Four models for low-impedance applications Three "Ti" versions include low-impedance and isolated 25, 70, and 100 volt outputs for distributed audio systems Rear panel gain controls for tamper resistant operation with 2 dB detents for quick and repeatable settings XLR and detachable Euro style input connectors DataPort V2 for use with DPV2-compatible signal processing accessories (XC-3, SF-3, LF-3) and DSP-3/DSP-4 (with external power supply) Independent defeatable clip limiters for reduced distortion Selectable high-pass filters protect speakers and prevent speaker transformer saturation with minimal effect on program material (30 Hz or 70 Hz on non-"Ti" models, 50 Hz or 75 Hz on "Ti" models) Front panel indicators include power, signal, and clip Covered barrier strip output connectors for safety agency compliance Automatic variable-speed fan for quiet normal operation with maximum cooling on demand Rear-to-front air flow keeps equipment racks cool Stereo, Bridge, or Parallel operating modes Comprehensive protection circuitry including DC, infrasonic, thermal overload and short circuit protection 3-year warranty plus optional 3-year extended service contract Specifications: 8 ohms 20Hz-20kHz 0.1% THD: 185W 4 ohms 20Hz-20kHz 0.1% THD: 280W 2 ohms 1kHz 1% THD: 430W 70V or 100V 50Hz-16kHz 0.5% THD: 300W 25V 50Hz-16kHz 0.5% THD: 200W Bridged Mono 8 ohms 1kHz 0.1% THD: 600W Bridged Mono 4 ohms 1kHz 1% THD: 830W 140V or 200V 50 Hz-16kHz 0.5% THD: 600W Signal to Noise (20Hz-20kHz): 100 dB Distortion (SMPTE-IM): < 0.01% Input Sensitivity @ 8 ohms: 1.15v (+3.4 dBu) Voltage Gain @ 8 ohms: 33.4x (30.5 dB) Output Circuitry: Class AB Distortion (Typical): * 20 Hz-20 kHz: 10 dB below rated power: Less than 0.03% THD, 4 ohms and 8 ohms * 1.0 kHz and below: full rated power: Less than 0.03% THD, 4 ohms and 8 ohms Frequency Response, 10dB below rated output power: 20Hz-20kHz, +0/-1dB, -3 dB points: 5 Hz + 50 Hz Damping Factor (Direct Outputs): > 250 @ 8 ohms Output Regulation: < 1.5 dB Input Impedance: 10 k ohms unbalanced, 20 k ohms balanced Input Clipping: 10 Vrms (+22 dBu) Cooling: Continuously variable speed fan, back-to-front air flow Connectors, each channel: * Input: Active balanced; 3-pin Euro-style detachable terminal block and XLR (pin 2+) * Output: Covered barrier strips * DataPort V2: HD-15 connector Controls: * Front: AC switch * Rear: Ch. 1 and Ch. 2 gain knobs, 10-position DIP switch Indicators: PWR-ON Green LED, SIGNAL Green LED (1 per channel), CLIP Red LED (1 per channel) Amplifier Protection: Full short circuit, open circuit, thermal, ultrasonic, and RF protection; Stable into reactive or mismatched loads Power Requirements: 120, 230, VAC, 50-60 Hz Load Protection: On/off muting; Triac crowbar: ISA 750 Rack-mount size: 3 RU Dimensions: 19" x 5.25" x 15.9" (48.3 x 13.3 x 40 cm) Weight: 44 lbs. (20 kg) Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted January 3, 2014 Share Posted January 3, 2014 (edited) The only drawback that I can see using a Proamp is the fan noise. The the cost of under$12.00, it can be done. Buy two Neutrik speakon connectors (4 slot) from Monoprice or Parts Express. This will take 5 min. to connect ot bare speaker wire. Then get two 1/4 in. XLR connectors to place on the preout cables from the avr and connect to the Proamp. This should work without a problem. Some people power their whole system with Proamps. My Behringer amps are 7 lbs and are used for my subs. I have entertained using all class D Proamps. Edited January 3, 2014 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
BlackGTS Posted January 4, 2014 Author Share Posted January 4, 2014 The only drawback that I can see using a Proamp is the fan noise. The the cost of under$12.00, it can be done. Buy two Neutrik speakon connectors (4 slot) from Monoprice or Parts Express. This will take 5 min. to connect ot bare speaker wire. Then get two 1/4 in. XLR connectors to place on the preout cables from the avr and connect to the Proamp. This should work without a problem. Some people power their whole system with Proamps. My Behringer amps are 7 lbs and are used for my subs. I have entertained using all class D Proamps. Thanks for the info. Fan noise will NOT be a problem. I am buying this amp to give me a chance to open up these speakers before they go into the HT. I'm talking about Pink Floyd, Three Days Grace, Disturbed, and anything else that I want to turn up. The way I see it, if I can hear the fan then I am doing something wrong Ron Quote Link to comment Share on other sites More sharing options...
pzannucci Posted January 4, 2014 Share Posted January 4, 2014 The Denon is rated at 125 watts per channel. For 2 Channel mode that should be plenty for the RFs. I'm not sure you would gain any quality with the qsc amplifier. You would probably loose sound quality trying to plug in a different amp unless it was of very high quality and at least 200 good watts. Save the money toward something better and figure out why your Denon isn't appropriate with the RFs. I doubt just a new amp (in particular that one) is really going to solve the problem (this from someone who is always looking for a silver bullet). 125 watts when run in stereo should be more than adequate for quite loud. 250 watts will get you just a little louder. Even in the review of the AVR-4802 they stated the difference between the older Denon at 170 watts and the 4802 for 125 watts was insignificant (power to loudness wise). Secondly, considering the vintage of the receiver, you probably want to start the front end (DAC, connections, and conversion) and get something like a Pioneer SC series that is rated for solid power and 4 ohm loads with a speaker that dips as low in the impedance as an RF-83 likely does. Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted January 4, 2014 Share Posted January 4, 2014 QSC makes some very nice pro amps that sound very good. Namely, the PLX amps. As long as your preamp or AVR can drive the amp, they work great. The amp that you are looking at states that it is a "cost effective solution." You should try to listen to it first. It may have more power but sound very bad. I don't know but you do not want to be disappointed. FWIW, you can pick up a used PLX for about $400 or $500 and keep it forever (even as a backup it is nice to have). Or, as stated above, your AVR may be up to the task already. Quote Link to comment Share on other sites More sharing options...
Rivernuggets Posted January 4, 2014 Share Posted January 4, 2014 I have a QSC PLX 1104 and 2502 that get hooked up here and there. Fun to mess around with and sound excellent. I don't know the ISA 300T. Listening to it before buying is paramount in this case. You'll need these RCA to XLR cables for the Denon to the QSC ISA 300T: http://www.monoprice.com/Product?c_id=115&cp_id=11509&cs_id=1150902&p_id=4777&seq=1&format=2&utm_expid=58369800-11.KFcpHWqASSutMqNPOqaJVg.0&utm_referrer=http%3A%2F%2Fwww.monoprice.com%2FSearch%2FIndex%3Fkeyword%3Drca%2Bto%2Bxlr Looks like you don't need speakon connectors with that QSC. Quote Link to comment Share on other sites More sharing options...
BlackGTS Posted January 4, 2014 Author Share Posted January 4, 2014 Thanks for the info guys. I am probably going to wait for the equipment that I will use in my HT. As much as I want to really let these speaks breathe, I don't want to just buy something that may not work out. There's no real way for me to test this amp with my 83's so I think I will hold off for now. Thanks for all of the advice, Ron Quote Link to comment Share on other sites More sharing options...
Marvel Posted January 6, 2014 Share Posted January 6, 2014 The only drawback that I can see using a Proamp is the fan noise. The the cost of under$12.00, it can be done. Buy two Neutrik speakon connectors (4 slot) from Monoprice or Parts Express. This will take 5 min. to connect ot bare speaker wire. Then get two 1/4 in. XLR connectors to place on the preout cables from the avr and connect to the Proamp. This should work without a problem. Some people power their whole system with Proamps. My Behringer amps are 7 lbs and are used for my subs. I have entertained using all class D Proamps. It also has barrier strips for the speaker outputs. This is the same as the connections on the heritage crossovers. Bare wires will work here. Bruce Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted January 6, 2014 Share Posted January 6, 2014 Thanks Bruce. Quote Link to comment Share on other sites More sharing options...
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