Monoprice Retro Balanced Conversion Guide

[Max_Settings]

For those of you who saw my Monoprice Retro review will probably remember I converted my set to balanced. So when @Densetsu sent in his set to have the same done, I decided I would make a guide.

 

For starters here's what you need. The headphones, 2 2.5mm female jacks, 4 strands of solid copper wire taken from a CAT6A cable, a lighter, soldering iron, solder, flux, screwdriver set, scissors, a thumb tack, needle nose pliers, side cutters,wires strippers, vice grips, a vice, file, drill, hot glue gun, and heat shrink.

Start by removing the pads. Simply give them a pull and they will come off.

Then take notice that the two stickers will be at the back of the headphones for reassembly. Next you will need to remove 4 screws. Place them in a parts tray. Repeat for both sides.

This is what you should have afterwards.\

Next to get farther into the headphones you have to remove the 2 Monoprice stickers. To do so, you will see a tiny gap at the bottom. Take a thumbtack and insert it there. Then simply make a complete rotation all the way around and peel up the sticker on both sides. Set them aside for later.

Left side.

Right side.

Next on both side you need to remove a plastic cover by removing 3 screws. Once you do you will see this.

At this point you are free to cut off the stock wire with a pair of scissors.

Now on the left side you should be left with this.

At this point if you only want to do a detachable wire mod it is very easy. Take a lighter and burn off the enamel coating on the 3 wires. On the 2.5mm connector pictured below you will see 3 terminals. 2 are parallel from each other, a silver and gold, and another silver one at the bottom. Solder the red wire to the the silver terminal, the blue wire onto the gold one, and the copper color one onto the silver ground lug at the bottom. Skip way towards the end of this guide to see what to do next.

You will have to unscrew a large screw on both sides to get the headband off. Now you have some glue and solder to melt on both sides. Take your soldering iron and melt the glue off the two end of the headband. Once you do you have an option of either desoldering the wires from the headband or cutting them off, either will work.

Once you have the wires removed from the headband and it completely off, try and remove as much excess glue and wire from the ends as possible.

In order to not risk your new wires from making connection to the headband wires, take 4 small pieces of heat shrink and cover the 4 ends on the headband

Your next issue is the glue holding the wires into the cups. Take your soldering iron and melt the glue in the hole and the wires should be able to pull through.

Then you should be left with the wires on the drivers. You can desolder the two off of both drivers at this point.

Now for the hardest part of the entire mod, modding the caps. The two caps that were on the left side and right side are different. The left side already has a hole to accommodate the stock wire, but it is too small for our 2.5mm connector. The right side has no hole, so we have to make one. Also on the under side of the right cap there is a mountain of plastic in the center, that gets in the way of the connector, that has to be ground out of there to make room. The left cap has nothing in its underside thank goodness.

For these next steps you want to go outside or into a garage because it will get very messy with plastic dust and shavings. The first thing you want to do is cleanup and slightly enlarge the hole that you burned the glue out of for the wires to come through.

Next go into your vast selection of drill bits and pick whatever you think is best for grinding. I didn't have a sander bit, but if you do that's what I would recommend.

Now these next steps aren't pretty, but all this is internal and will never be seen. You have to take a drill and grind out half of this mountain of plastic on the side near the hole for the wire.

Once you have do that take a file and start expanding out the hole, and stop every so often to test fit. You have it right where the cap and the cup can meet with the connector inside and not rock back and forth, so a flush fit.

You also can grind down the little bit of plastic in the U-shaped part of the cup to more clearance. Same on both sides.

On the right side cap you will see the notch from where you put the tack in earlier, line up over that and sit back and file out a hole to fit the connector.

When you are done it should look something like this.

Now back to the 2.5mm connectors. For this mod we will not be using the ground lug. That is because it interferes with screwing back on the headband. So take a pair of sidecutters and snip it off. This results in only being able to use 2.5mm mono plugs.

Next thing you want to do it put the connectors in a set of vice grips to hold them for soldering.

Then strip the ends of your wires. The colored one should be +, going into the hole on the silver terminal. And the white wire should be - going onto the gold one. Stick the wires through the holes and solder them on. Repeat on both sides.

When you are done soldering, take some hot glue and place it on the ends. This will ensure a safer connection and prevent wires from crossing.

Now take the wires with the connectors soldered to them and feed them through the holes in the cups you drilled out.

Next thing you need to do is solder the colored wire to the red + terminal on the driver, and the white - wire to the white terminal. Cover with hot glue when done.

Next thing to do is put the cups back together. Tuck the wire into the cup and close them up. Remember to put the sticker at the backs, so think which way is which on both cups. Then screw back the 4 screws. Try to have the connectors facing relatively the right way.

Next, position the connectors the right way. Some will stay in place with friction when you put the cap on, and others will need a dab of hot glue under them to hold.

Now put the headband back on. This can be a bit tricky because it goes under the connectors. Don't put too much hot glue to hold them because it will block the headband. For the people who did only the detachable cable mod, you will be somewhere around here. Since you didn't remove the headband, just mount the connector you soldered and follow mostly along from here.

Once you have everything in place, screw back on the caps.

Then simply put back on the Monoprice stickers and you are done.

Just add back on the pads and congratulations, you have a balanced converted set of Monoprice Retros!

I hope this guide was helpful to everyone. I will link a few of the things used here below.

 

Monoprice Retro

2.5mm Connectors

Brainwavz XL Pads

Periapt Cables

 

 

 

 

[dizmo]

Beautiful.

 

Now, when does the thread go up in the Buy and Sell section with this as a service?

[Max_Settings]

7 minutes ago, dizmo said:

Beautiful.

 

Now, when does the thread go up in the Buy and Sell section with this as a service?

I am doing this a service. I didn’t do this set for free. It’s just that very few people are willing to pay more for a balanced conversion than what the entire headphone costs.

[dizmo]

6 minutes ago, Max_Settings said:

I am doing this a service. I didn’t do this set for free. It’s just that very few people are willing to pay more for a balanced conversion than what the entire headphone costs.

Interesting. What are you charging? 

I can't think of many services this intensive that would cost less than $25 haha. I wonder what you could sell them for, completed, on eBay. 

[Max_Settings]

9 hours ago, dizmo said:

Interesting. What are you charging? 

I can't think of many services this intensive that would cost less than $25 haha. I wonder what you could sell them for, completed, on eBay. 

It would have to be at least $50. This takes me at least 4 hours to do.

[dizmo]

54 minutes ago, Max_Settings said:

It would have to be at least $50. This takes me at least 4 hours to do.

I'd almost say that's selling yourself short! Very interesting though. I'll definitely keep this in mind.

This with a custom headband would be pretty unique.

[Spuriae]

Thanks for the internal images. That pretty much confirms that the Monoprice Retro is from iSK. Probably an HP-980 rebrand.

Spoiler

https://www.head-fi.org/showcase/isk-hd9999-fully-enclosed-monitoring-headphone-with-carry-case.21200/reviews?direction=asc#reviews

The Superlux HD662/B/F use what looks like the same driver and similar housing but have a different damping sticker.

[Max_Settings]

1 hour ago, Nimrodor said:

Thanks for the internal images. That pretty much confirms that the Monoprice Retro is from iSK. Probably an HP-980 rebrand.

  Reveal hidden contents

https://www.head-fi.org/showcase/isk-hd9999-fully-enclosed-monitoring-headphone-with-carry-case.21200/reviews?direction=asc#reviews

The Superlux HD662/B/F use what looks like the same driver and similar housing but have a different damping sticker.

Possible, but the 980 has a detachable wire.