Drop + THX AAA™ 789 Linear Amplifier Discussions | Drop

Sep 19, 2019

Can someone explain to me which gain is appropriate for my 100 impedance headphones, II or III? I feel like III gives more punch if compared to II at about the same volume but maybe it's just the fact that I know that III is louder by default.

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Sep 19, 2019

Eli38It depends on your input voltage. Gain iii can only accept 2.1v unless you attenuate 7db input at the source. Gain i and ii can handle up to 7v input with no attenuation at the source. With that settled then it comes to which output are you using balanced or single ended headphones as the power level roughly doubles between them both. From there you you want to use whatever you feel gives you good wide volume adjustment control. There is is no appropriate rule for gain vs headphone impedance. The main idea is gain i is for sensitive IEM’s, gain ii you will probably use most of the time, gain iii is for more power hungry headphones. I can can drive my 150 ohm 58X single ended DAC input 2.1v, single ended headphone output on gain ii for general usage and gain iii when I want more output into my earholes. My 32ohm 4XX need way more power and using single ended DAC 2.1v input gain iii, balanced output gives me more than balanced input 4.3v gain ii balanced output.

Sep 19, 2019

LisasonictowerThank you for such a thorough post! I feel dumb after reading it.:) i own a pair of Sennheiser HD26 Pro and a well know TinAudio T2. I got lost after you mentioned 2.1v. Where is it coming from or how do I check this setting?

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Sep 19, 2019

Eli38The input voltage from a DAC, that is presuming you are using a DAC. Stereo RCA pair 2.1v(olt) balanced pair 4.3(volt) That is based on the Grace SDAC-B but most DAC’s are similar in voltage output. To to simplify my answer previously, IEM’s mainly use gain i, mainly use gain ii otherwise for headphones, if you run out of volume adjustment increase the gain.

Sep 19, 2019

Eli38Also gain is a function of how much the amplifier multiplied the input voltage to output voltage which is why you feel it has more punch but mainly because it’s louder.

Sep 20, 2019

LisasonictowerThank you so much for explaining! You are also a psychic, I use Grace SDAC-B via RCAs.

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Sep 20, 2019

Eli38In that case then using RCA’s feel free to use any gain you desire with no worries what so ever. would I be correct thinking you have the SDAC balanced outputs going to some powered monitors or something else as you don’t have them wired from the DAC into the 789?

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Sep 20, 2019

LisasonictowerThe RCA's from SDAC (USB connection) go straight to the THX 789!

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Sep 20, 2019

Eli38I hear you my friend. But why are you not also using the balanced output on the DAC into the 789 as well? Do you have the SDAC or SDAC-B?

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Sep 20, 2019

LisasonictowerOh, I wish. I learned that I need balanced cable and not all headphone support them. Anyway, I almost purchased DT1990 but some experienced people I believe so said that SDAC balanced is not truly balanced hence it has only one chip and on top of that not all headphones sound good with a balanced cable, in my case I heard that DT1990 is not the best option for that. Not sure if some of that is true or not but I really wanted to have it balanced that's why I purchased it in the first place. But I love how it sounds right now anyway.

Sep 20, 2019

Eli38Without getting into the semantics of is the DAC truly balanced or not balanced because that’s splitting hairs. You can can run the balanced cables from DAC to amplifier to benefit from the increased voltage as spoken above previously. You also dont don’t need to use headphones balanced with doing this. All amplifier inputs work on all amplifier outputs. By increasing the input voltage you won’t need to use as much gain or volume knob gain which should keep the signal cleaner. It won’t drastically change the sound and it will still sound the same. It just unlocks more potential. You can unlock more again by using balanced headphone wiring. My point being don’t limit your system as you have more room to grow with it yet, you have many more options.

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Sep 20, 2019

LisasonictowerI leaned so much from your responses keeping in mind that I didn't know much at all.:) If I understand correctly, let's say I have my Gain set to II at 50% volume and if I switch to balanced cables which are ok to use with non balanced headphones (cable) the volume what was set to 50% will be louder? If that's the case would you happen to know where can I buy very short XLR cables?

Sep 20, 2019

Eli38Yay I feel useful for once 😉. I do realise I’m not always the easiest to understand. You are absolutely correct in your in your assumption of how an increased voltage input works. And when you do use balanced headphones your wattage output doubles too. Both will give you that more “punch” you like plus more of everything. Have a read of postwarscars review he just shared. Im not a believer in cable voodoo but I bought my short cables from amazon. You need 3 pin male XLR to 3 pin female XLR and you may need to buy 2 as some are sold per single cable unlike RCA leads where a single cable has both left and right channels. Because it’s balanced cables from a differential DAC it can support long cable runs without picking up interference so it’s ok to use long length cable if you felt the need to.

Sep 20, 2019

LisasonictowerI'm glad there are knowledgeable people like you who a willing to help others!:) Now, I can get those XLR cables I wanted. Regarding long and short ones, I wanted the short one just because they will take less space and they are cute just like my SDAC, lol. Thanks again!

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Sep 20, 2019

Eli38Happy to try and help if I can with any knowledge I do have, even if it isn’t as much I know or can explain fluidly like many others are able to.

Sep 20, 2019

LisasonictowerI went with LyxPro cables since Mogami and Canare are to expensive for the purpose I think. I also thought what’s the point of having expensive cables if my headphones cable is probably cheap. Well, that’s an excuse I came up with.:)

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Sep 20, 2019

Eli38Honestly people speak about cables altering the sound in ways that only a wizard could create like they are the most important aspect in audio. A good quality well made cable that will last is all you need. A badly made cable can affect the sound negatively way more than any tiny gains can be had from the quite frankly seriously over priced offerings. You have zero justification to make. I’ve changed my IEM cables to braided because they are super flexible and pliable which is good for comfort. I use super cheap Yinyoo cables. For my 58X I have. Scrap explaining here is a photo. They all sound the same as stock except for single ended vs balanced.

Sep 20, 2019

LisasonictowerCan’t agree with you more! Thanks for sharing a photo, I enjoy looking at stuff like that and what others have.

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Sep 20, 2019

Eli38It’s all thrown together at the moment after a move so it’s a disaster but I’m going to sort it all out next week. Here is another angle that shows the true potential of said disaster lol

JJayJJ

472

Sep 20, 2019

LisasonictowerSONY VTC 18650 batteries, a charger, some unidentified liquid, a coil of wire, scissors for cutting wicks? Thats that vape life! Btw loving that sick looking cable on the headpones. Who did those for ya?

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Sep 20, 2019

LisasonictowerAll the goodies. I have the same battery charger!😄 And I believe that white box is from the SDAC, I didn’t put mine away.

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Sep 20, 2019

JJayJJYep haha you nailed it except for the scissors, those would be for my nails obviously, the framed staple wire requires proper cutters. The silver cable on the 4XX? If so that is a yinyoo one, the one on the IEM is yinyoo too but the silver one is overall thicker. On the advertising photos they both look identical but different prices.

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Sep 20, 2019

Eli38It’s a fantastic charger Xtar VC2S it charges super quick. The box is actually a optical and coaxial input to 3 optical output switcher so I can connect my CD player and optical from my TV without having to keep switching cables on the back of the SDAC. I wish they had made it Airist R2R sized with individual inputs, the small cuteness is the very thing I dislike the most of this DAC lol.

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Sep 20, 2019

LisasonictowerOh, that is very handy! Yes, the charger is great, takes a lot battery types. You just gave me an idea that not only I can use my SDAC with PC but other media devices as well! Did’t think about that since I spend most of the time behind a PC.

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Sep 20, 2019

Eli38Yes absolutely, anything that has a digital output.

Sep 22, 2019

LisasonictowerJust received and trying the balanced XLR cables and I was blown away by how much more power I got from using them! I switched to gain I 60% of the volume instead of gain 2 50% of the volume!

Sep 22, 2019

Eli38That’s awesome news !!! When you switch to balanced headphone output the difference is twice as big than what you just experienced.

Sep 22, 2019

Eli38Whilst you can, don’t use gain 3 with balanced input selected unless you attenuate 7db in your source.

momotan

Sep 24, 2019

Lisasonictowerdarn i learnt so much from this discussion. i'm obviously an audio nub and have exactly the same set up (thx 789 otw and sdac balanced) and have a pair of zmf aeolus (1/4 inch input). have a few questions which i hope you can give me some advice for: (i) any good recommendations on where to get "3 pin male XLR to 3 pin female XLR"? (ii) also do you reckon i would need to recable my zmf to xlr? (iii) playing music from my computer so my dac get plugged into my PC via? cheers mate :D

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Sep 24, 2019

momotan(i) - just have a look on amazon for the XLR cables. (i) - if you want to use the full amps capacity rather than half then by all means change to XLR headphone cable but I haven’t seen or used your headphones nor googled them. (i) - you would normally use the USB connection but any can be used if it has optical/coaxial but they all use different bit and sampling rates which I know nothing about as a PC is my last choice of source to use.

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momotan

Sep 24, 2019

Lisasonictowerthanks lisa!

Sep 24, 2019

LisasonictowerYep, I tried on the low and it was a bit too much. By the way, what are the reasons not to use III - distortion and potential damage to the dynamics and obviously the hearing?😄

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Sep 24, 2019

Eli38The voltage input limit on gain 3 is 2.1v and at some point from there it will clip the input signal. Gain 1 and 2 have a higher input voltage limit at 7v.

Sep 24, 2019

momotanWelcome to the conversation! I got my LyxPro XLR cables from Amazon but then returned them since the quality wasn’t to my standards. Initially, I wanted to get Mogami or Canare or Belden but they were making them to long therefore expensive. I needed 1.5f length. Luckily I found this great website that makes custom length cables of these brands using original parts for half the price if not more. So, I got myself Mogami cables the ones I wanted for $56. Here is the link. https://www.ghentaudio.com/part/list-xlr.html Regarding the PC. I tried both Optical and USB cables. There is no difference soundwise that you will hear. Optical output is limited to 44.1kHz and 24bit if I eemember correctly whereas USB is 32bit and has some very high kHz number I couldn’t even remember, lol. You can change those setting with a right mouse click over the sound output. But it all depends on the audio source. If you are listening to Spotify then 44.1kHz is all you need but if Tidal then you can go way higher than that. Setup your output to kHz to match your audio source. Technically USB might get electrical interference whereas optical output not but that is a rare issue. There are other factors like how long you can run each type of cable but that doesn’t concern us. The main reason I went with USB cable is that it keeps the audio source untouched by Windows. Meaning it goes from the source straight to the DAC whereas with Optical it goes through you built in audio chip which is not great and then to the DAC.

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