[myphone]

Bought the amp during after-Thanksgiving sale ($329).

Have been running for a week. Very nice platform.

No noise at all, with original tubes or NOS tubes.

All preliminary listening was done with NOS tubes, GE 5670 driver tubes and various power tubes.

The amp could easily drive various phones, Fortex, HD 650, Beyerdynamic T1 etc.

Flavors of different phones are very apparent.

Different output tubes (many brands 6080, 6AS7 and WE 421a) flavors are also very apparent.

Preliminary assessment: very nice and versatile.

 

[Allanmarcus]

Bought the amp during after-Thanksgiving sale ($329).

Have been running for a week. Very nice platform.

No noise at all, with original tubes or NOS tubes.

All preliminary listening was done with NOS tubes, GE 5670 driver tubes and various power tubes.

The amp could easily drive various phones, Fortex, HD 650, Beyerdynamic T1 etc.

Flavors of different phones are very apparent.

Different output tubes (many brands 6080, 6AS7 and WE 421a) flavors are also very apparent.

Preliminary assessment: very nice and versatile.

Thanks for the impressions. Any comparisons to other amps?

 

[hall.cullen]

I just purchased one of these and so far I have to say I very much enjoy the sound. On my personal Computer (windows 10 64-bit) it works like champ and integrates with no driver issues at all. Windows 7 64-bit is what my office computers run and its not been pretty. When first connected windows failed to find a suiteable chipset driver for the Savitech SA9227 USB chipset and just didnt work. I contacted technical support and they gave me the try updating the drivers, use a different port, try and different PC advice, however, of course none of that produced any results. I asked about drivers and they said there are not any. I did manage to get it working with windows 7 by downloading and installing the Savitech drivers found here (https://support.hifimediy.com/suppo...vitech-sa9227-uda38pro-uda18-uh1-uh1-digital-). Now that I have sound out of it, its still finiky as it seems to force every application that wants to send it sound into "exclusive" mode, so for example if outlook wants to make a sound that I have a new e-mail that is the only applicaiton that can send the device audio. I have to un-plug and re-plug to get it avaible again and even that is a bit questionable. Its possible the drivers I downloaded are to blame as it seems they are not exacly what is called for, however, it does indicate an issue that drivers may be needed in windows 7.

I contacted tech support at Monoprice and told them this and the seemed uninterested and said effectivly glad you got it going bye.

So far the sound / price ratio is good enough for me to keep going, however, my willingness to mess with the drivers will soon wane....

 

[lgcubana]

Just skimming Monoprice for some more info on the just released THX 887 and came across this:
on sale, $189.90 with free shipping
https://www.monoprice.com/product?p_id=29511

 

[mrcalypso]

Hey I just picked this up last week as an early Christmas present and I am very happy especially for 190$! This is built like a brick and weighs a ton ( about 22 pounds) Looks wise it leaves much to be desired basically looking like a Mini PC tower but at least it looks better in real life than online. I'm using the amp with my old trusty Sennheiser HD580's with HD 600 grills and they go really well together and bring out the potential of these headphones. Initially it sounded good but after an hour or so the sound started opening up and now it sounds smooth like butter but with some sugar on top. I can listen to it forever and now I'm hooked and stay up late every night just to listen to it. The only other headphone amp I've had is the Kicas Caliente years ago which I loved and not sure if that is a fair comparison but the Monolith Amp is on a whole different stratosphere of sound. I can't wait to change the tubes bc most people say their amps don't sound good with the stock tubes but this one already sounds great. I hear no noise at all and everything is crystal clear with amazing soundstage and incredibly smooth sound.

 

[mrcalypso]

Bought the amp during after-Thanksgiving sale ($329).

Have been running for a week. Very nice platform.

No noise at all, with original tubes or NOS tubes.

All preliminary listening was done with NOS tubes, GE 5670 driver tubes and various power tubes.

The amp could easily drive various phones, Fortex, HD 650, Beyerdynamic T1 etc.

Flavors of different phones are very apparent.

Different output tubes (many brands 6080, 6AS7 and WE 421a) flavors are also very apparent.

Preliminary assessment: very nice and versatile.

Hey I'm a newbie to tube rolling and just got this recently. Which tubes do you recommend I replace them with? Monoprice is selling Electro Harmonix 6922EH Vacuum Tube would that be a good one for this amp?

 

[dpump]

Hey I'm a newbie to tube rolling and just got this recently. Which tubes do you recommend I replace them with? Monoprice is selling Electro Harmonix 6922EH Vacuum Tube would that be a good one for this amp?

No, you cannot use 6922 tubes in this amp.

I've had this amp for 11 days now. This amp is a steal at the $189.90 price; price even includes free shipping. I have a number of other tube headphone amps, some of which cost much more than this one. It pretty much holds its on or equals all of them. The stock tubes sounded pretty good. I then tried 3rd generation Western Electric WE 396A, but replaced them with Russian 6N3P-DR. The stock tube is a 6N3; the 6N3P-DR is a heavy duty military tube which I also use in the Loxjie P20 and the Garage1217 Ember. I love this tube, but you will probably have to order them from eBay. They're aren't very expensive, but you have to wait a while to receive them since most come from Russia, Serbia, and Ukraine.

For the output tube I tried GE and RCA 6AS7. Then I tried a Toshiba 6080 and it was totally quiet and sounds fine to me. I would recommend the 6080 over the 6AS7 as the 6AS7's I tried had a bit of noise, although the noise seemed to get less and less with more burn-in. No noise you could hear when the music was playing, only with no signal and the noise was very low. No hum, just the normal tube noise you sometimes get with NOS tubes until they have some use.

For the price, this amp is a no brainer. Buy it and try it stock. Upgrading tubes isn't terribly expensive if you decide to keep it. This amp is similar to the Bottlehead Crack or Darkvoice since they both use the 6AS7/6080 output tubes. The big difference is that the Monoprice is transformer coupled and has switchable output impedance, so you can use phones from 32 ohms to 600 ohms. I've tried phones both 32-60 ohms and 600 ohms and they all worked fine. The Monoprice tube amp is one of the best purchases I have ever made for a tube headphone amp. I highly recommend it.

 

[Shane D]

No, you cannot use 6922 tubes in this amp.

I've had this amp for 11 days now. This amp is a steal at the $189.90 price; price even includes free shipping. I have a number of other tube headphone amps, some of which cost much more than this one. It pretty much holds its on or equals all of them. The stock tubes sounded pretty good. I then tried 3rd generation Western Electric WE 396A, but replaced them with Russian 6N3P-DR. The stock tube is a 6N3; the 6N3P-DR is a heavy duty military tube which I also use in the Loxjie P20 and the Garage1217 Ember. I love this tube, but you will probably have to order them from eBay. They're aren't very expensive, but you have to wait a while to receive them since most come from Russia, Serbia, and Ukraine.

For the output tube I tried GE and RCA 6AS7. Then I tried a Toshiba 6080 and it was totally quiet and sounds fine to me. I would recommend the 6080 over the 6AS7 as the 6AS7's I tried had a bit of noise, although the noise seemed to get less and less with more burn-in. No noise you could hear when the music was playing, only with no signal and the noise was very low. No hum, just the normal tube noise you sometimes get with NOS tubes until they have some use.

For the price, this amp is a no brainer. Buy it and try it stock. Upgrading tubes isn't terribly expensive if you decide to keep it. This amp is similar to the Bottlehead Crack or Darkvoice since they both use the 6AS7/6080 output tubes. The big difference is that the Monoprice is transformer coupled and has switchable output impedance, so you can use phones from 32 ohms to 600 ohms. I've tried phones both 32-60 ohms and 600 ohms and they all worked fine. The Monoprice tube amp is one of the best purchases I have ever made for a tube headphone amp. I highly recommend it.

So, do you have this and the Cayin? There is an open box right now for $199.00. I don't need a DAC, but at that price, it would be cool to try out a tube amp.

 

[dpump]

If the open box amp at $199 has free shipping and returns I would give it a try. I don't know how Monoprice works for you in Canada. Do they ship from Canada or the USA?

 

[Shane D]

If the open box amp at $199 has free shipping and returns I would give it a try. I don't know how Monoprice works for you in Canada. Do they ship from Canada or the USA?

The US, so no free shipping. When I bought an open box Liquid Spark it only had 30 day replacement and a 90 day warranty.

 

[Relaxasaurus]

I bought an open box 1060C from Monoprice before and it was pretty much new. Had a great experience and would personally recommend their open box options.

 

[Shane D]

I bought an open box 1060C from Monoprice before and it was pretty much new. Had a great experience and would personally recommend their open box options.

Same with me on the Liquid Spark. Dirt cheap and I love that little amp.

 

[Or Astroman]

I snapped one of these up in early December when it was just $189(looks like it's back at $399 now)and I feel like it's a honey of a deal. It seems like it's just now coming into it's own as far as breaking in goes. I use it with the Sennheiser HD6XXs mostly and it has a warm yet lively character that engages me easily. I don't have many other amps to compare it with but it is a completely different presentation than the iFi Hip dac which has proven detailed and a bit more forward than the Monolith. I was using a combo of Magni 2U with a USB Monica from DIY Paradise(a NOS Dac) before the Monolith amp came in and I haven't done a head to head with those two but if pressed I'd say the Schiit/Monica combo was a little more rhythmically forceful but a tiny bit bare where textures are concerned. The Monolith is a bit more relaxed but has more "meat on the bone" with textures and never really turns harsh to my ears.

I did swap the tubes. Swapping out the driver tubes for some GE 5670Ws made the most difference. The built in DAC is good but a tiny bit sterile sounding to me. I'm using a Raspberry Pi with an Allo Boss Dac for a source and that sounds much better for my ears. That's another bonus with this Monolith unit, the extra inputs. I have a DAC input free for my laptop should I want it and another line in on the front for a DAP or something else.

Bottom line is I think it's a pretty good deal at the $399 list price but keep an eye on it to see if the price drops south of $200 again. Then it's a killer deal!

 

[SaltyLinuxGreybeard]

For anyone who finds this thread and is having humming issues:
Modify the USB cable to not receive power and it's dead quiet. Use electrical tape to cover the outer contacts on the end that plugs into your PC.
If you're adventurous you can also open it up and clip zip ties to remove things like DAC output being zip tied to high voltage transformer output.

After doing this I have zero hum with any headphone.

I'm not sure why this amp never took off. Transformer coupled, able to drive low impedance low efficiency planar headphones effortlessly, and once you crack the amp open it's incredibly well laid out and easy to repair/have repaired. Any guitar tube amp shop will be able to fix this thing.

Finally received NOS Sovtek 6a7sg and paired with 2x United 2C51 and holy hell the mids are amazing. Blows the stock tubes out of the water! Tibre and decay are far improved.

I was trying some NOS GE 6080s and WE JAN 6080s with Reflector 6N3P-DR which definitely gave a more OTL vibe. Incredibly warm but poor control with the power planar headphones need.

If anyone has another recommendation for a OTC tube amp for <$1k I'd be interested. The Cayin HA-1 mk2 piques my interest but as far as I can see the Monolith is simply a clone of that/possibly the same OEM.

 

[CADCAM]

This is $199 again free shipping you guys still think it's worth getting?