Fun with T-amps - I didn't know what I was missing.

[sendler]

MeanWell Power supplies sound great

The only problem I'm running into is kind of tangential - the switched-mode power supplies I've tried all seem noisy and send a whine through the amp. I've tried a 19V 6A, 12V 11A, and 24V 11A bridged supply, and they are all noisy to some extent (these are notebook PC power supplies). On the battery, the amp is nearly silent.

The MeanWell SMPS that Sure is selling for less than a good tranformer sound great.
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http://cgi.ebay.com/36V-DC-9-7A-349-2W-Switching-Power-Supply-EMS-FREE-/230468091482?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item35a8f7fe5a

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Get the 36v SMPS and use the front panel adjuster to turn it down to 32v which is the optimum voltage for the amps. No noise whatsoever, the fan never runs, 33 degrees C inside the case, very efficient and sounds much better than the big linear supply that I had been using for all of my other amp trials. A modified Sure 2X100, TK2050 amp with a MeanWell supply is a real eye opener. Explosive dynamics and very transparent. Much better than any of my gainclones.

[[email protected]]

Re: Fun with T-amps - I didn't know what I was missing.

any opinions on this http://www.amazon.com/gp/product/B00...1WZS9QFDXN2QXD or this http://www.amazon.com/gp/product/B00...02BWNS3DT49GZ6

[absolootbs]

Re: Fun with T-amps - I didn't know what I was missing.

any opinions on this http://www.amazon.com/gp/product/B00...1WZS9QFDXN2QXD or this http://www.amazon.com/gp/product/B00...02BWNS3DT49GZ6

re: the preamp, i would think you'd wanna do a little better on the low end than a 40hz f3.

[WWWJD]

Re: Fun with T-amps - I didn't know what I was missing.

I thought about going wood but I wasn't sure if I could get it to not look stupid. Plus wood has no interference rejection, so what do you do, line the wood panels on the inside with sheet metal or what?

FWIW, I've been running mine open chassis with no shielding; haven't had any interference problems, and it's quiet as a mouse.

[[email protected]]

Re: Fun with T-amps - I didn't know what I was missing.

what about the gemini? above. got my sure amp and power supply already. now i just got to figure it out. no volume knob like with the little pe t-amp. this amp even comes with an optional chip fan.







thats why im asking about a pre-amp. the gemini is $78 and has bass, mid, and treble adjustments.

[danklugherz]

Re: Fun with T-amps - I didn't know what I was missing.

what about the gemini? above. got my sure amp and power supply already. now i just got to figure it out. no volume knob like with the little pe t-amp. this amp even comes with an optional chip fan.







thats why im asking about a pre-amp. the gemini is $78 and has bass, mid, and treble adjustments.

Hi Arlis, Pre-Amps are recommended for the Sure boards, because of their higher input voltage make sure your gain setting is set to low. You can read about it here.

http://www.sure-electronics.net/download/AA-AB013_Ver1.2_EN.pdf

Dan

[[email protected]]

Re: Fun with T-amps - I didn't know what I was missing.

that was very helpful, thanks for the link dan.
sounds like a preamp is the way to go.

[philiparcario]

Re: Fun with T-amps - I didn't know what I was missing.

the cheapest passive preamp is this.


this is a full range stereo pot. 1 stereo input 1 stereo output

http://cgi.ebay.com/PAC-LC-1-LC1-Remote-Volume-Bass-Sub-Control-Knob-New-/140356303617?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item20ade33b01#ht_967wt_1139

this is a little lower

http://cgi.ebay.com/PAC-LC-1-LC1-Stereo-Remote-Level-Controller-Bass-Knob-/290433680055?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item439f3242b7#ht_1471wt_1139

still lower

http://cgi.ebay.com/SCOSCHE-EFX-CAR-AMP-REMOTE-LEVEL-CONTROL-BASS-KNOB-RLC-/370267263747?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item5635a61303#ht_4016wt_913

even lower

http://cgi.ebay.com/UNIVERSAL-AMPLIFIER-BASS-KNOB-GAIN-CONTROL-MTX-KICKER-/120574819173?cmd=ViewItem&pt=Car_Amplifiers&hash=item1c12d1bb65#ht_1882wt_913

on the hi end of the same idea

http://cgi.ebay.com/GOLDPOINT-SA1-STEREO-PRECISION-PASSIVE-PREAMP-RCA-/150428189797?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2306380465#ht_1124wt_913

one more thing you would be surprised on how good those 10 to 15 dollar ones are. you can buy 2 and use them as independent left right volume controls..

all of the above just lower the signal to the amp. a lot of cd players have a 2 volt signal these work well with them.

[[email protected]]

Re: Fun with T-amps - I didn't know what I was missing.

intresting find phil.
i curently have a bid on a onkyo 3160.

[tom_s]

Re: Fun with T-amps - I didn't know what I was missing.

Hey Arlis,

I'm in a cleaning mode and I have an old Kenwood KC-207 preamp that a co-worker gave me a while back. He shorted one of the outputs on the matching amp and let the magic smoke out.:( I'm pretty sure this preamp works just fine and you can have for free. It's not the greatest piece in the world, but I don't think it's really all that bad- it was part of a mid-line rack system I think. It even has a remote!:D I'll hook it up for a quick test tonight.

[[email protected]]

Re: Fun with T-amps - I didn't know what I was missing.

thats very kind of you tom. if i dont win my bid on ebay, i'll take you up on that. i bet i could swing up that way this thursday.

[tom_s]

Re: Fun with T-amps - I didn't know what I was missing.

Well, I just tested this...and I'm sorry if I got your hopes up. It has an issue! Hums like crazy on one channel. It's not really worth digging into, so it looks like it's headed for that great equipment rack in the sky...:(

[[email protected]]

Re: Fun with T-amps - I didn't know what I was missing.

thats cool. if i dont win the onkyo, i may just go ahead and get the gemini through amazon.

http://www.amazon.com/gp/product/B0000C8CFU/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B00004UFQJ&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0K8B271WZS9QFDXN2QXD

[[email protected]]

Re: Fun with T-amps - I didn't know what I was missing.

phil, do you know anything about this.

http://www.electronickits.com/kit/complete/ampl/k100.htm

it would be cool to imcorperate the pre right into the same enclosure.

[sendler]

Pot

Most people building amps from modules just include a potentiometer on the input.
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http://www.diyaudio.com/forums/class-d/143669-sure-electronics-new-tripath-board-tc2000-tp2050-140.html#post2157868

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Use a low value such as 10k and keep any wiring following the pot to a minimum in order to reduce the interactions with the passive volume control.