So it has arrived, and guess what, it is different. Guess I will have to refer to this as the Green Board!
I have studied the pictures of the black board too closely, but I can see the inductor in the middle of the pre section is a different value, but it still has Nichison Gold and Elna power caps, so maybe just an iteration.
Any way it sounds fine. I'll let it play for a while and then compare it to my Tisbury passive/Quad 306 that I use in my office.
I have studied the pictures of the black board too closely, but I can see the inductor in the middle of the pre section is a different value, but it still has Nichison Gold and Elna power caps, so maybe just an iteration.
Any way it sounds fine. I'll let it play for a while and then compare it to my Tisbury passive/Quad 306 that I use in my office.
Attachments
Seems you have the same version of bushellj :
Signal Input to Op-Amps are TK "Audio" Caps 10uF 50V
Signal Output from Op-Amps are Nichicon Gold 10uF 16Volt.
and other changes...
The "Tilera PCB" is fully Elna equiped.
Thanks for the pictures (TOP = "Tilear" PCB)
Last edited:
Hi Lee (and Danny),
Looks like you have received the identical board that I received earlier this week.
Yes the caps look similar as Danny already stated and the Inductor on the 12 Volt Power Supply seems to be 10uH rather 22uH used on the original board.
You just need to update the Op-Amps to OPA1656 as I think we all now accept that they sound better than the original NE5532. I have a pair already on adapters if you want some - Same as I provided to Danny. Just PM me.
In comparison to my TPA3255 based model (Aiyima A07) The TPA3251 (Aiyima A04) certainly appears to be the better option. Having the Anti-Pop circuit is probably the prime advantage !! Both mine have been upgraded with OPA1656.
Even the Output inductors actually look better made on the TPA3251 model !!
Just running both at 30Volts from a Mean Well LRS-200-24 SMPS the TPA3251 appears to give better bass - maybe because the main Power Supply Caps are 3 times the capacity at 6,000uF as opposed to the 2,000uF on the TPA3255 model.
As for Power output (from the Data Sheet) the TPA3251 provides 100W at 4ohm and 50W at 8ohm. The TPA3255 provides 65W at 4ohm and 50W at 8ohm - All at 30Volt Supply Voltage. My KEF Q15 Speakers are rated at 6ohm.
The gain of the TPA3255 is 21.5dB whereas the TPA3251 is 20dB so not a lot of difference in the specification. I think my TPA3251 actually sounds a bit louder at a given position of the volume control. As we don't have a circuit diagram for these boards we don't know if there is any gain at the Op-Amp stage or if it is the same between the two boards.
So unless the TPA3251 isn't loud enough for you the TPA3251 would seem to be the better option for most domestic situations. I can certainly annoy the wife at anything above half volume !! My primary source is a Mac Mini just using the headphone port.
Have fun with your new toy.
James.
My friend's new Aiyima TPA3251 2.0 amp
I finally received delivery of my friend's new Aiyima TPA3251 2.0 amp from Amazon.com. I had ordered it from Amazon over a month ago, and I'm not sure if COVID-19 is to blame, but Amazon stated that the units were in stock, so I am not sure why it took so long to deliver it.
Anyway, I plugged the unit into my main system as a power amp and listened to it for a few hours. As with my unit and another friend's unit, the amp is thin on the bass, a bit sibilant in the highs, and basically, it just isn't exciting musically.
I extracted the stock NE5532 op amps and installed a pair of double OPA627AU op amps mounted on DIP8 adapters from eBay seller alice1101983, and the tone was warmer with a smoother presentation and more extended bass. The sound stage went from flat and forward to three dimensional with significantly better separation. The amp was definitely more enjoyable with the new op amps.
However, I was not finished, and proceeded to remove the red speaker binding posts hook-up wire and replaced it with Duelund DCA16GA 16ga Tinned Copper wire with waxed Cotton insulation. I had run out of my favorite Cardas quad eutectic solder, and used Kester 44 solder instead to solder the wires in place, and touch up all the other solder joints of all through-hole components in the signal path including the RCA connectors, capacitors, inductors, etc.
I gave everything more time to burn in and it is impressive how the little bit of wiring can improve the sound quality. I played Laurie Anderson's soundtrack from the concert film "Home of the Brave," and the music was more lively compared to when I listened to the amp prior to changing the wire. Maybe it was simply touching up the solder joints. All I know is that it sounds much better now.
Considering that I spent about $95 on the amp, op amps, some wire and a 32V DC/5A switching power supply, it makes a very affordable gift for my friend who just moved to Brazil to work with underpriviledged youth in the inner cities. I wanted to give him something that was compact and energy efficient, yet can drive his vintage speakers with ease.
I hope the TPA3251 amps that bushellj and LeeHibbert purchased sound as good as the Aiyima "black board" TILEAR HD325X Rev. 2.1 unit with Toshin Kogyo UTSP and Elna Starget Red Robe caps. It's unfortunate that the Chinese manufacturer(s) of these amps cannot ship what they advertise. As daniboun previously advised, it might be best to spend the extra money to get the "black board" TILEAR HD325X Rev. 2.1 unit.
I finally received delivery of my friend's new Aiyima TPA3251 2.0 amp from Amazon.com. I had ordered it from Amazon over a month ago, and I'm not sure if COVID-19 is to blame, but Amazon stated that the units were in stock, so I am not sure why it took so long to deliver it.
Anyway, I plugged the unit into my main system as a power amp and listened to it for a few hours. As with my unit and another friend's unit, the amp is thin on the bass, a bit sibilant in the highs, and basically, it just isn't exciting musically.
I extracted the stock NE5532 op amps and installed a pair of double OPA627AU op amps mounted on DIP8 adapters from eBay seller alice1101983, and the tone was warmer with a smoother presentation and more extended bass. The sound stage went from flat and forward to three dimensional with significantly better separation. The amp was definitely more enjoyable with the new op amps.
However, I was not finished, and proceeded to remove the red speaker binding posts hook-up wire and replaced it with Duelund DCA16GA 16ga Tinned Copper wire with waxed Cotton insulation. I had run out of my favorite Cardas quad eutectic solder, and used Kester 44 solder instead to solder the wires in place, and touch up all the other solder joints of all through-hole components in the signal path including the RCA connectors, capacitors, inductors, etc.
I gave everything more time to burn in and it is impressive how the little bit of wiring can improve the sound quality. I played Laurie Anderson's soundtrack from the concert film "Home of the Brave," and the music was more lively compared to when I listened to the amp prior to changing the wire. Maybe it was simply touching up the solder joints. All I know is that it sounds much better now.
Considering that I spent about $95 on the amp, op amps, some wire and a 32V DC/5A switching power supply, it makes a very affordable gift for my friend who just moved to Brazil to work with underpriviledged youth in the inner cities. I wanted to give him something that was compact and energy efficient, yet can drive his vintage speakers with ease.
I hope the TPA3251 amps that bushellj and LeeHibbert purchased sound as good as the Aiyima "black board" TILEAR HD325X Rev. 2.1 unit with Toshin Kogyo UTSP and Elna Starget Red Robe caps. It's unfortunate that the Chinese manufacturer(s) of these amps cannot ship what they advertise. As daniboun previously advised, it might be best to spend the extra money to get the "black board" TILEAR HD325X Rev. 2.1 unit.
LeeHibbert,
- All you have to do is remove all four hex head screws from the rear plate and the four hex head screws from the front plate.
- Remove the top plate of the chassis.
- You'll also need to remove the Phillips head screw that mounts the RCA phono jacks to the rear plate.
- After that, you can gently pull the rear plate with speaker binding posts from the phono jacks, and swing the rear plate up and out of the way of the bottom half of the case.
- Then you should be able to slide the bottom half of the case rearward to remove it.
Rich
Perfect instructions, got the bottom off. I wanted to unscrew the heatsink to see if there was a revision number hidden by it, but they have sealed the screws.
The green board has Rubycons and Nichison. It would be fun to compare, but since James and myself are in the UK, that won't happen any time soon. Mind you I fancy doing some gravel riding in South Carolina, so I could always bring my bike and 'Green Board'.
Perfect instructions, got the bottom off. I wanted to unscrew the heatsink to see if there was a revision number hidden by it, but they have sealed the screws.
The green board has Rubycons and Nichison. It would be fun to compare, but since James and myself are in the UK, that won't happen any time soon. Mind you I fancy doing some gravel riding in South Carolina, so I could always bring my bike and 'Green Board'.
@bushellj
I've been running it today on a 24v I have. I will play it with a 32v/5A tomorrow. I don't need much volume as I am only in my office room about 13x13ft, I will compare it against Tisbury passive pre + Quad 306 going into Celestion SL6s. However I will try it on some Magnapan SMGa and hear how it goes!
I have ordered the same OPA627AU as @rhing . In truth I have lurked on DIYAUDIO for years and know I have similar music taste as Rich so went with what he prefered.
I've been running it today on a 24v I have. I will play it with a 32v/5A tomorrow. I don't need much volume as I am only in my office room about 13x13ft, I will compare it against Tisbury passive pre + Quad 306 going into Celestion SL6s. However I will try it on some Magnapan SMGa and hear how it goes!
I have ordered the same OPA627AU as @rhing . In truth I have lurked on DIYAUDIO for years and know I have similar music taste as Rich so went with what he prefered.
Now we're talkin'. All's left to do is replace the two power supply caps. I've played with TPA amps since before the 3116 mega-thread. Both the value and type of PS cap used in these TI amps is audible from my experience over the years.
Curious what you would recommend trying. I’ve read that these TI TPA-325X Class D amps are less sensitive to the choice of PS caps, but I have not really investigated this myself.
Oh the usual, Elna/Muse/Panasonic etc. Wonder where you read that, I haven't seen any feedback on PS caps with the 325- series. At the very least worth a try with the Aiyima as I don't have much confidence in the quality control in those cheap designs.
Enjoy seeing you post again. No longer tinkering much myself, but check in from time to time.
Hi Lee.
I have had some OPA627AU on order from the same supplier as Rich since I ordered my original TPA3255 unit but they still haven’t arrived yet !!?? It will be interesting to see the comparison with the OPA1656. I am certainly not short of bass with these Op-Amps but then I don’t expect much from my little bookshelf speakers. One day I might have the time to try some more serious speakers - I have some old Epos ES14’s in the loft which are notoriously difficult to drive but used to sound good when set up right.
I have found that my enjoyment of music with both these amps has really come done to the quality of the source material - they are that transparent. I ripped loads of CDs some years ago but find that the newer HQ material on You Tube typically sounds better. I have not yet tried hooking up my old Arcam CD Player which was my default source before the Mac Mini took over and I now stream everything - the CDs just stay in the cupboard !! Just seems too big and clumsy now !
Those Epos are great speakers. Too good to keep in the loft.
The 3251 is much better than a 3116 I previous had running. The difference is what Rich described when he changed opamps. Compared to the 3116, the 3251 has space and depth and it easier to follow the different strands in the music, and this is using a cheap Behringer USB DAC. I plann on getting a Topping DAC which should take it up another level.
The 3251 is much better than a 3116 I previous had running. The difference is what Rich described when he changed opamps. Compared to the 3116, the 3251 has space and depth and it easier to follow the different strands in the music, and this is using a cheap Behringer USB DAC. I plann on getting a Topping DAC which should take it up another level.
Agreed. The Epos ES 14’s are nice stand-mounted monitors that should work well with the TPA3251, even at 86dB efficiency. The impedance between 10-20kHz hovers between 7-8 ohms, so the stock inductors are fine, assuming they’re are 12.5uH. I would recommend a loosely twisted pair of the Duelund DCA16GA hook-up wire as speaker cables. Just connect them as bare wire—no spades or banana plugs.
Thanks Rich for your inputs.
Unfortunately the ES14 speakers only provide a pair of banana plug sockets on the back. One pair directly connected to the bass unit (no crossover components as it is a mechanical low pass filter !!) and one pair to the tweeter with just an inline capacitor to filter off the low frequencies - very simple !!
Have to see if I can find the Dueland DCA16A wire in the UK. I currently use Swedish Supra speaker cables which seem to work well. I previously used Naim speaker cables but they are so stiff that it makes them impractical to use in most domestic situations
HiFi Collective have it. Duelund | Hifi Collective
This guy uses 12GA for speaker and 20GA for home made interconnect. https://theaudiobeatnik.com/duelund-dca-tinned-copper-cables-part-4/
I ordered the Aiyima 3251 from Amazon after reading through everyone's posts here and at Audio Circles and received it yesterday after 3 weeks .
Wow, for fifty dollars it is a bargain . Thank you for the tips to this amp.
It is the black pcb model and appears well made and clean .
I used a 24 volt smps as the 32 volt one I have didn't want to fit the Aiyima's power plug with it's pin .
Today I am going to order a 32 ps from Altima.
There does not seem to be a lot of bass , lean in that department although I am using Seas 8 inch full range speakers.
I am transitioning from class A and class AB tube amps to something with a single knob that my wife can operate that isn't a heat pump in summer.
Listening to a CD of the Rhino Best of the Searchers there is excellent sound although it can't match the depth of sound that my tube amps had.
Which opamps are upgrades over the stock one that are direct replacements without adaptors ?
Thanks
Wow, for fifty dollars it is a bargain . Thank you for the tips to this amp.
It is the black pcb model and appears well made and clean .
I used a 24 volt smps as the 32 volt one I have didn't want to fit the Aiyima's power plug with it's pin .
Today I am going to order a 32 ps from Altima.
There does not seem to be a lot of bass , lean in that department although I am using Seas 8 inch full range speakers.
I am transitioning from class A and class AB tube amps to something with a single knob that my wife can operate that isn't a heat pump in summer.
Listening to a CD of the Rhino Best of the Searchers there is excellent sound although it can't match the depth of sound that my tube amps had.
Which opamps are upgrades over the stock one that are direct replacements without adaptors ?
Thanks
From only my experience, I would consider the OPA627AU or OPA1655 op amps, but they can only work with adapters. The adapters actually make swapping op amps very easy. There are probably dual op amps in PDIP-8 packages like the stock NE5532 op amps that can improve frequency response, especially, especially with bass. Certainly, the OPA627AU op amps will provide sound quality that you would prefer.