Every once in a while you stumble across a product that looks so appealing you need to have it at home. Such is the case with the DIMD PP10 tube amplifier from Latvia. Originally designed by a music lover and engineer for his wife who is a musician, and later refined and cased in an aluminium and wood sculpture, it attracted a lot of interest at a recent Dutch audio show. At home however, I soon found that the small power tubes on top could not drive my very low efficiency loudspeakers loud enough, so some alternatives were borrowed. This ended up in weeks filled with music flowing around my listening room and a roundup of how various speakers perform when driven by the DIMD amplifier.
The PP10 is a push-pull class A/B vacuum tube integrated amplifier with four inputs. Each channel of the tube circuit uses an ECC83 double triode for voltage gain and as phase splitter for a pair of EL84 power pentodes. These are connected to the output transformers in an ultra-linear configuration and deliver 10 Watts per channel. The top, front and rear panels are machined out of aluminium, while the base is made out of wood. The front has volume control, source selector and power on/off switch. The tubes can be kept naked or covered in tube cages, adding another dimension to the DIMD’s appearance. On the back are a power inlet and fuse holders next to four RCA inputs and loudspeaker terminals, all of them silver plated. There’s no remote control; when you need to adjust the amplifier you have to stretch your legs.
On the inside is a hard wired circuit with, amongst other components, polypropylene capacitors and 1% metal film resistors. Volume control and source switch are both by ALPS. A large toroidal transformer is used for the power section, while the output transformers are of the classic shell type. DIMD claims to source all components from the EU, Switzerland and Japan.
The source I used was Bluesound Node 2 streaming my music into a NAD M51 D/A-converter. At first I used my Harbeth P3ESR loudspeakers, but their low 82dB sensitivity meant that volume levels were limited. The next step was to use Finalé Audio Vivace Mini loudspeakers, an interesting design with only one 2.75inch full range driver in a cleverly designed horn cabinet. Since only one driver is in used for the whole frequency range no crossover is necessary, this keeps phase problems to a minimum and makes for a true point source. The Vivace Mini has a high impedance of 15 Ohms, which is perfect since it will draw less current, but drops the 10 Watt output to just five! Nevertheless with an efficiency of 93dB it could play fairly loud. Next in line is a pair of Audiovector SR3 Avantgarde Arreté full range, two and a half-way speakers. These have a 91.5dB sensitivity and a nice 8 Ohm nominal impedance. With a sealed box, a horn and a vented design results were very different, but always enjoyable, allowing the PP10 to show off its capabilities and drag you into music.
The Finalé Audio Vivace Mini was very interesting as long as I kept my music choice to vocals, baroque, small jazz combos and easy on the ear pop music. You simply cannot expect to play metal or symphonic orchestras with one small driver. On some Lori Liebermann tracks all the acoustic instruments seem to have correct tone and the voice is almost as I remember from her concerts. The midrange is very open and this is where the PP10 is shows how tender, smooth and at the same time dynamic and detailed the EL84 tubes can be. Leonard Cohen’s voice is deep and cracks when he speaks, the background vocals come forward easily and the only limit is the power. You cannot play very loud, the Vivace Mini won’t handle it and gets a bit rough. This might have to do with the limited power of the PP10 or probably even more with the character of the Vivace. Turning to pop music ‘Ride Across The River’ by Dire Straits plays very, very fast and detailed with a nicely arranged stereo image. It lacks deep bass of course, but what happens above about 60Hz makes you forget about the lowest notes. The same happens with an MQA recording from the Tingvall Trio called ‘Beat’. On this download are tracks like ‘Hamnen’ with piano and ‘Spksteg’ with a lot of percussion and bass. Both are full of attack, lightning fast and show what the direct coupling of a single driver to the amplifier output can do for leading edges. Piano sounds clear if bit light of tone but it’s still natural. Percussion adds those harmonics a cymbal has, dynamics jump from the drums and the bass. Again bass does not go very deep, but it remains detailed with good separation of the wooden parts and the plucked strings. ‘Spksteg’ really gets me moving when I turn up the volume. Finishing with Chet Baker and a lot of baroque music I could easily recommend this combination to music lovers with smaller listening rooms.
Now you might get the idea that the Vivace Mini is star of the show, but it’s the DIMD PP10 that does all the driving. My Harbeths sound different and show more of the PP10’s capabilities when it comes to voices and/or classical music. Due to the limited power volume levels are limited to 90dB in my listening chair, but for late night listening this is more than enough. The neutrality of the P3ESR lets me judge the PP10’s tonality, character and voicing. Being a lover of the EL84 tube I find myself almost in heaven. The PP10 reveals lots of detail, sounds very neutral and is above all very musical. Instruments sound lifelike and the way you would expect of the recording. Voices are real when I compare them to what is left in my memory of live concerts. Music is so very enjoyable that I kept forgetting the time and stayed up too late for my own good on a number of occasions. Still, the little Harbeth is not what I would recommend with the DIMD, although it sounds great it simply lacks the volume and dynamics that more powerful amps can extract. Yet I can imagine some people getting hooked on the pureness and natural voicing.
Big loudspeakers bring big sound. Could this also be true for the DIMD PP10 and the Audiovectors? The distributor brought some Audiovector cables along with the speakers, cables that are optimized for tube amplifiers and have the same characteristics as the wire inside the enclosure. A little bit of toe-in is enough for a deep stereo image and I sit down in my chair to play ‘Nardis’ from Patricia Barber’s Café Blue, the piano notes in the slow introduction sound very refined to my ears and keep up with the rest of the instruments as they join in and the music speeds up to the drum solo. Being used to having the drums very loud on a Pass Labs and PMC combination I get about 90% of the experience while levels still peak at almost 100dB. Most impressive however is the speed of the amplifier, with the cymbals on the left hand side every strike is separated from the next, with no smearing. The MQA version of ‘Spksteg’ by the Tingvall Trio on the Audiovectors is by far the best yet with the PP10 as powerhouse. Bass gets a bit messed up due to the amp’s low damping factor but above problematic frequencies for the room we have drums and piano almost fighting for attention, with no winner in the end since they are both stars of the performance. It sounds so very real and this time with more than enough loudness. The opening track of the same CD is more subtle with less energy and this brings out the charm of the amplifier and its EL84 power tubes. There’s never a dull moment, nor any shouty harshness or other misbehaviour from the amplifier (or speaker). The PP10 might not be everyone’s friend, yet its inherent quality cannot be denied. After more jazz and a lot of voices, both male and female, I turn to classical music again to round off the review. One of the CDs in my collection is a flute concert by Sharon Bezaly, composed by W.A. Mozart, in a performance backed by the Ostrobothnian Chamber Orchestra (Flute Concertos, Rondo, Andante BIS). Bezaly is sometimes called the Horowitz of flute for her musicality, what could be a more perfect final act for an amplifier that delivers musicality day after day? What seemed impossible with the Finalé Audio speakers, reproducing a full orchestra, is not a problem with the Audiovector S3 Avantgarde Arreté on the DIMD. The stereo image is wide, with correct height and deep enough to satisfy. Bezaly’s flute stands clear of an orchestra that is nicely spread behind her, almost from wall to wall. Music does not hang onto the baffles, speakers fade away when the music starts. Neither the flute nor the violins ever become harsh, they shine in a lively and appealing way.
What looked like a pretty face at the audio show turned out to be so much more at home. It’s very easy to fall in love with the DIMD PP10 amplifier and its little EL84 tubes, it’s not a chrome plated eye-catcher, it is more a sculpture filled with musicality. Most important of course is how the PP10 plays your music. Let me say that on all three pairs of speakers music is extremely enjoyable, but you need speakers that have efficiency above 90dB for the best results. Or maybe not the best, but you will be able o play any kind of music at realistic levels at home. The 10 Watts will never become the tenfold or more so many amps do offer these days, but ask yourself what you need, because musicality, detail, speed, neutrality and tonal richness might be more important than sheer power. I could think of a few reasons why you might hesitate to buy the DIMD PP10: in most countries you have to order it direct from the manufacturer, power is limited, it is not cheap etcetera, but you cannot blame the amplifier for that. I have heard so many amps, both tube and transistor, very, very good ones amongst them, but not that often have I heard so much sheer love for music in every note. Within my systems with my speakers it is a no go, but I can imagine many other setups in which the DIMD would shine. For instance the Audiovectors are great with this amp. When I received the amp it came fresh out of the box and needed running in. In the weeks that followed it worked perfectly, channel balance was always excellent, it never turned hot or made plops or clicks, all proof that the PP10 is a reliable product that should give many years of listening pleasure. I wish I were capable of designing such a present for my wife.
Operating mode class: AB
Output topology: Push-Pull, UL
Output tubes: 4 x EL84
Driver tubes: 2 x ECC83
Nominal speaker impedance: 6 or 8 Ohm
Maximum power: 2 x 10 Watt
Inputs: 4 RCA pairs
Input sensitivity: 420 mV
THD @ 1W (1kHz): < 0.1 %
THD @ 10W (1kHz): < 0.3 %
Frequency response (+0/-0.5 dB): 20 - 20 000 Hz
Power bandwidth (+0/-3.0 dB): 10 – 40 000 Hz
Dynamic range: 90 dB
Stereo crosstalk @ 1W: -65 dB
Output impedance @ 1W: 2.8 Ohm
Global NFB: 6 dB
Mains voltage: 230 VAC / 50 Hz
Power consumption: 100 W
Dimensions: 430 x 159 x 280 mm
Weight: 9 kg