My "First Watt" experiment

[Cornman]

I have had the First Watt product on my top ten list to try out for several year's. So as I said in the earlier thread "Nelson Pass First Watt" , after reading all the positives expressed by Cask 05 ( who also has Jub's) I placed my order last week. Packaged arrived yesterday in good shape & I put it in the line up.

Oh what a disappointment, the sound was so boomie, so unclear, I could not stand to listen to more than two songs. Cked all the connections, tried some output level adjustments on the dx38, nothing helped. I really find it hard to believe a amp of this caliber & reputation could sound this bad. I hope to speak with Cask & Mark at Reno audio where I purchased this refurbished unit. Perhaps there is something defective with this one, or could it be that I have never correctly set up my DX38, I have reviewed my setting's several times & all appears correct but as I have said before being a old dog - I am insecure with digital programing & such. So it is possible I never correctly set up the DX38, but if that's the case I dont understand how it sound's pretty dang good with the other amps that I have tried with the Jubs.. Huuuum..??..

If any of you stereo guru's in the area (Travis, Chris, Luther) especially anyone with DX38 experience have time to stop by & do an audit of the DX settings & sound I would be so grateful.

Happy Holidays to all,

Cornman

[PrestonTom]

Let's be clear on this

1. Make sure your dx38 settings are correct and sound okay using another amp.

2. Which First Watt model are you using? The diffent versions have different goals (eg, one of them does not provide volatge gain for instance).

3. What did the guys at RenoHiFi suggest?

Good luck.

[Cornman]

Preston, it's the F3 model. I just shoot Mark at Reno hifi a email a few minutes ago, waiting for his suggestion's.

Cornman

[mikebse2a3]

Are you using the F3 on the K402/TAD and if so, what amplifier are you using on the Jub LF?

Do you know the input sensitivity rating of the amplfiers you are using?

From your description of the sound I believe you will need to make level adjustments to acheive a proper balance between the Jub LF and K402/TAD.

mike tn

[PrestonTom]

Out of curiosity.... you are using a dx38, so you must be bi-amping. Is the F3 for the K402/TAD horn? and what is being used for the bass bin?

I checked and the F3 has about 13 dB gain and a sensitivity of 650 mV giving 1 watt (at 8 Ohm). Were you okay with your calculation of the "compensation" required for the amp for the bass bin (it is unlikely to have the same gain and sensitivity as the F3). RENO HiFi can help you out on that setting, since the dx38 will need to "know" the gain between the two sections.

EDIT: It looks like Mike types (and thinks) faster than I do. He beat me to it.

[mikebse2a3]

tried some output level adjustments on the dx38, nothing helped

Did you use the Analog Level Controls(Knobs) or did you adjust levels in the EV program?

For a quick level adjustment by ear (to get you in the ballpark anyway) I would suggest you turn the EV DX38's analog level controls for the Jub LF channels down very low and while listening to a good vocal recording bring the levels back up until you begin to hear a very natural voice reproduction.

mike tn

[seti]

Did you ditch the vk60?

[Chris A]

Quote

If any of you stereo guru's in the area (Travis, Chris, Luther) especially anyone with DX38 experience have time to stop by & do an audit of the DX settings & sound I would be so grateful.

Here are my Dx38 settings for all four channels - screen by screen - for 2-way Jubs with TAD TD-4002 drivers on K-402 horns being driven by a First Watt F3 amplifier on channels 2 and 4, and the bass bins driven by a Crown D-75A on channels 1 and 3 (in MY room, all rotary dials at the 12:00 "0" position):

(CORRECTED 15 August 2014)

IN1: Master EQ1, Type: PEQ f: 92 Hz, Q:1.5 Gain: -3dB

IN1: Master EQ2, Type: PEQ f: 4.2 KHz, Q:2.0 Gain: -1dB

IN1: Master EQ3, Bypass

IN1: Master EQ4, Bypass

IN1: Master EQ5, Type: PEQ f: 100 Hz, Q:4.0 Gain: -5dB

IN1: Master Delay, Delay:1917us, Unit: us

IN2: Master EQ1, Type: PEQ f: 92 Hz, Q:1.5 Gain: -3dB

IN2: Master EQ2, Type: PEQ f: 4.2 kHz, Q: 2.0 Gain: -1dB

IN2: Master EQ3, Bypass

IN2: Master EQ4, Bypass

IN2: Master EQ5, Type: PEQ f: 100 Hz, Q:4:0 Gain: -5dB

IN2: Master Delay, Delay: 1917us, Unit: us

IN1+2: Master Delay, Delay:1917 us, Unit: us

Out1: Routing, Source: IN1, Label:Lo

Out1: Channel EQ1, Type: PEQ f: 180 Hz, Q:12 Gain: -4dB,

Out1: Channel EQ2, Type: PEQ f: 300 Hz, Q: 12 Gain: -4dB

Out1: Channel EQ3, Type: PEQ f: 370 Hz, Q: 4.0 Gain: +1dB

Out1: Channel EQ4, Type: PEQ f: 700 Hz, Q: 16 Gain: -10dB

Out1: HIPASS XOVER, Type:thru

Out1: Lopass Xover, Type: Linkwitz 24 dB, f: 450 Hz Pol:Norm

Out1: Channel Delay, Delay: 0.0us, Unit: us

Out1: Compressor, Thrsh:8.70V Rat:1/1.0, Attack: 99ms Rels: 50ms

Out1 :Limiter, Thrsh:8.7V, Release: 50ms

Out1: Level, Level: 0.0dB, Polarity:normal

Out2: Routing, Source:IN1, Label:HI

Out2: Channel EQ1, Type: PEQ f: 370Hz, Q: 8.0 Gain: -10dB

Out2: Channel EQ2, Type: PEQ f: 660Hz, Q: 1.5 Gain: +3 dB

Out2: Channel EQ3, Type: LOSLV f: 2.5kHz, Slope: 12dB Gain: -1dB

Out2: Channel EQ4 ,Type: LOSLV f: 5.4kHz, Slope: 12dB Gain: -10dB

Out2: Hipass Xover, Type: Linkwitz 24 dB, f: 400Hz Pol: norm

Out2: LoPass Xover, Type: thru

Out2: Channel Delay, Delay:2271us, Unit: us

Out2: Compressor, Thrsh: 8.70V Rat:1/1.0, Attack: 99ms Rels: 50ms

Out2: Limiter, Thrsh: 8.70V, Release:50ms

Out2: Level, Level: -3dB, Polarity: normal

(Output3 repeats the Output1 settings, Output4 repeats the Output2 settings)

Let me know if you see any errors or omissions.

 

EDIT 25 Nov. 2016: For those of you using newer crossovers, such as a XIlica XP series, here are the settings.  First, the TAD TD-4002 channel settings:

 

 

And the Jub bass bin settings (which are more variable from room to room, but these tame the 100-200 Hz issues that I had with the basic Jubilee settings):

 

 

Chris

[Cornman]

Bat 5i Preamp, Sophia Electric 91-01 -300B mono block amp's; &
Crown K2 powering the bass bins.

Using the F3 only for the K402/Tad's & the Crown on bass bins.

[Cornman]

Seti, I stiill have the VK60 & would be using it but it has developed some noise issues & need's a little sevice or else I would still be using it. The Bat is the best all around amp I have used so far.

Cask, thanks for sending your DX settings I will compare them with the list I have been using.

Cornman

[Cornman]

Here is the download That Coytee was kind enough to provde me with. The spec's do not seem to match the ones you posted Chris.

??

DX-38 settings for Jubilee with K402 & TAD 4002.pdf
23K View Download

[mikebse2a3]

IN1: Master EQ1
Type:EQ f: 92 Hz
Q:1.5 Gain: -3dB

IN1:Master EQ2
Type:EQ f: 4.2 KHz
Q:2.0 Gain: -1dB

IN1:Master EQ3
Type: EQ f: 16.4 kHz
Q:5.5 Gain: -3dB

IN1:Master EQ4
Type: EQ f: 66 Hz
Q:4.0 Gain: +0dB

IN1: Master EQ5
Type: PEQ f: 100 Hz
Q:4.0 Gain: -5dB

IN1: Master Delay
Delay:1917us
Unit: us

IN2: Master EQ1
Type: PEQ f: 92 Hz
Q:1.5 Gain: -3dB

IN2: Master EQ2
Type: PEQ f: 4.2 kHz
Q: 2.0 Gain: -1dB

IN2:Master EQ3
Type: PEQ: f: 16.4 kHz
Q:5.5 Gain:-3dB

IN2: Master EQ4
Type: PEQ f: 66 Hz
Q: 3.0 Gain: +0dB

IN2:Master EQ5
Type: PEQ f: 100 Hz
Q:4:0 Gain: -5dB

Let me know if you see any errors or omissions.

Chris

Just to be clear the EQs I've marked in (Red) are not Roy's program and I assume are some Chris has found usefull in his system/room.

Roy's program does include this setting though that Chris hasn't listed here.

IN1: Master EQ1
Type:PEQ f: 32 Hz
Q:12 Gain: +7dB

Edited for clarity: Except for what I've still noted above all other corrections have been deleted since Chris has made the corrections to his orginal post.

[Cornman]

Thanks Mike, yes these are the ones I am using that were at the bottom of your post.

IN1: Master EQ1
Type:PEQ f: 32 Hz
Q:12 Gain: +7dB

[Chris A]

The spec's do not seem to match the ones you posted Chris.

 

I believe that the differences will be in the bass bins (output channels 1 and 3, input PEQs below 400 Hz). I took out the "hump" in the Jub bass bin response in my room using REW and a DEQ2496 working in tandem, which took a while to accomplish. I lastly transferred the new bass bin settings entirely into the Dx38 and checked them out using REW and the DEQ2496, i.e., two different testing methods: input up-sweeps and pink noise/automated EQ, until both methods showed no changes required to the Dx38 PEQ settings.

I leave my TH subs on all the time (see dark green trace below) and they have also been dialed in and crossed over at 40 Hz using a 24 dB/octave Low Pass crossover filter on the SPUDs. I can send you those settings, but I don't believe that those are going to help you in your setup.

The light blue-green trace is the raw, un-smoothed, in-room response of my Jubs in

their corners (without the 32 Hz boost) just in front of the tapped Horn

SPUD subwoofers, which are the red trace. The green trace is the

combined, EQed in-room response. All measurements are from my prime

listening position(s) at the center of the room (looking forward). The

lf response of the Jubs and SPUDs are much stronger as you move toward

the side walls.

Chris

Edited September 3, 2015 by Chris A

[Chris A]

Just to be clear the EQs I've marked in (Red) are not Roy's program and I assume are some Chris has found useful in his system/room.

Thanks Mike for doing "due diligence".

Chris

[PrestonTom]

I think we are going off-track, but I am not sure.

Did the set up (with the dx38 settings etc) "work" before the F3 was substituted?

If it did, then it is not the dx38. In that case go back to what Mike Tn and I were suggesting. Find the the specs for gain and sensitivity of the two amps. I have already listed what they are for the F3.

[mikebse2a3]

Your welcome cornman.

Since I now know you are using the K2 (which has it's own level controls and input sensitivity switch) for the LF then you can use them to get you close to a proper balance with the F3 amplifier instead of the EV DX38's analog level controls if you want to.

I don't see any way the F3 should give you a boomy sound(since it is only on the K402/TAD) unless there is a level balance issue(ie: to much from the LF) due to the amplifier's different gain/ input sensitivity.

mike tn

[Chris A]

Also this is the corrected Q setting for:

Out2:Channel EQ1
Type: PEQ f: 370Hz
Q: 8.0 Gain: -10dB

Also this is the corrected Freq for:

Out2:Hipass Xover
Type: Linkwitz 24 dB
f: 400Hz Pol: norm

Corrected above in the original posting.

[Chris A]

I think we are going off-track, but I am not sure.

Tom, Joe (the OP) specifically requested help on the Dx38 settings in his leading post: I don't think this is off-track. Miketn also makes a good point about relative amplifier gains.

Did the set up (with the dx38 settings etc) "work" before the F3 was substituted?

In my conversations with Joe, he did have a usable output using other hf amplifiers.

If it did, then it is not the dx38.

...If it isn't a gain issue or other Dx38 connection/PEQ/crossover issue, right?

Chris

[PrestonTom]

I think we are going off-track, but I am not sure.

Tom, The OP specifically requested help on theDx38 settings in his leading post: I don't think this is off-track. Miketn also makes a good point about relative amplifier gains.

Chris

I already admitted that I was not sure, but my question is very simple.

If the set up was "working" and then the the F3 was substituted, then the culprit is the F3. If this is the case, then there are two possibilities. Either the F3 is not a good choice, and I don't think that is the case. Or the F3 is not being implemented correctly, and the finger points to an error in adjusting the gains between the 2 different amps. This is what Mike and I are suggesting.

So, did the orignal set up (including dx38 settings) work as it should?

Note: Chris is also typing and thinking faster than I can.