Her dukker det opp noen utfordringer med redusert diskant har jeg forstått?
Skal bruke en lettdreven Lowther fulltone på 15 ohm (ikke bygget enda) på en Kingrex T-Amp som er på 20 watt (i beste fall) i 4ohm.
1) Hva kan jeg forvente mtp lyd/klang/forvregning?
2) Vil en trafo etter høytalerutgangene løse dette eller blir det en krykkeløsning?
3) Bør jeg like gjerne finne en god 4 ohms fulltone jo før jo heller?
4) Forklar gjerne problemstillingen på en svært enkel måte?
One of the culprits could be the demodulating output filter. The loudspeaker impedance is a component of the demodulating output filter that determines the high frequency cut off. If the cut off is designed too close to audio band, premature roll off could happen. If the output filter is designed with 4 Ohm speaker in mind, then when 8 Ohm or 16 Ohm speakers are connected, then an even earlier roll off will happen. Inversely, if a lower than the designed impedance speaker is added, then the high frequency response will be better. The Tang Band based full range driver speakers with 4 Ohm impedance and a rising high frequency response should be a very good match.
he best part that will allow you to try this out, not cost too much and is light enough to pack in seems to be the Hammond part 117K16 or 117K32. I am too lazy to figure out the ratios at the various taps so will give you this simple way to determine what to do. A ratio of 4:16 ohms is an impedance ratio of 4:1, Sq. rt of 4=2 so the voltage ratio is 2:1. Apply a measured voltage (6-12vac from AC type wall wart) into the whole winding from pin 1 to com then go down taps till you are getting a ½ voltage measurement to com. This pin and com will be your 4 ohm tap and pin 1 to com will be your 16 ohm output. A better way to connect it would be to connect the test voltage as above and then measure from 4–8 then 2-16, see if either of these are ½ voltage. If one is close use that as your 4 ohm input. Since the SI has a balanced output it would be better if it saw a balanced load including parasitics. If none of the winding combinations are close, the normal output winding can be added in series to either end to give you more choices.
These transformers are $17.93 ea from Allied but are a special order item. All the major stocking distributors have zero balance with Allied having the best prices.
The difference between the 117K16 and 117K32 is power handling and a couple of bucks in price. The 32 watt one will carry better base so should be worth the extra weight and cost.
Actual performance will be considerably better than specs would lead you to believe. This is due to using it at a greatly reduced power and using it as an autoformer.
Trafo
Skal bruke en lettdreven Lowther fulltone på 15 ohm (ikke bygget enda) på en Kingrex T-Amp som er på 20 watt (i beste fall) i 4ohm.
1) Hva kan jeg forvente mtp lyd/klang/forvregning?
2) Vil en trafo etter høytalerutgangene løse dette eller blir det en krykkeløsning?
3) Bør jeg like gjerne finne en god 4 ohms fulltone jo før jo heller?
4) Forklar gjerne problemstillingen på en svært enkel måte?
One of the culprits could be the demodulating output filter. The loudspeaker impedance is a component of the demodulating output filter that determines the high frequency cut off. If the cut off is designed too close to audio band, premature roll off could happen. If the output filter is designed with 4 Ohm speaker in mind, then when 8 Ohm or 16 Ohm speakers are connected, then an even earlier roll off will happen. Inversely, if a lower than the designed impedance speaker is added, then the high frequency response will be better. The Tang Band based full range driver speakers with 4 Ohm impedance and a rising high frequency response should be a very good match.
he best part that will allow you to try this out, not cost too much and is light enough to pack in seems to be the Hammond part 117K16 or 117K32. I am too lazy to figure out the ratios at the various taps so will give you this simple way to determine what to do. A ratio of 4:16 ohms is an impedance ratio of 4:1, Sq. rt of 4=2 so the voltage ratio is 2:1. Apply a measured voltage (6-12vac from AC type wall wart) into the whole winding from pin 1 to com then go down taps till you are getting a ½ voltage measurement to com. This pin and com will be your 4 ohm tap and pin 1 to com will be your 16 ohm output. A better way to connect it would be to connect the test voltage as above and then measure from 4–8 then 2-16, see if either of these are ½ voltage. If one is close use that as your 4 ohm input. Since the SI has a balanced output it would be better if it saw a balanced load including parasitics. If none of the winding combinations are close, the normal output winding can be added in series to either end to give you more choices.
These transformers are $17.93 ea from Allied but are a special order item. All the major stocking distributors have zero balance with Allied having the best prices.
The difference between the 117K16 and 117K32 is power handling and a couple of bucks in price. The 32 watt one will carry better base so should be worth the extra weight and cost.
Actual performance will be considerably better than specs would lead you to believe. This is due to using it at a greatly reduced power and using it as an autoformer.
T amp + 16 ohms speaker?
Hello, I am wondering is there any way to mod the T amp to play on 16 ohms speaker? right now when I hook up the T amp to my 16 ohms speaker, it distort greatly even in low volumne Thanks!
www.diyaudio.com
Trafo
117K32 Hammond Manufacturing | Transformatorer | DigiKey
Bestill i dag, sendes i dag. 117K32 – 8 Impedans – primær Ohm 25V Impedans – sekundær Ohm Lydomformere 100Hz – 9kHz Chassismontering fra Hammond Manufacturing. Priser og tilgjengelighet på millioner av elektroniske komponenter fra Digi-Key Electronics.
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