Modwright PH 9.0 X
Tube Phono Preamplifier
What’s Different in the PH 9.0 X?
PH 9.0X involves the addition of a pair of Lundahl gapped output transformers, commonly used in SET tube amps. The addition of these transformers also means the elimination of a pair of chokes and coupling caps, all in the signal path. This brings the performance of the PH 9.0 X closer to that of the PH 150 Phono Preamplifier.
With the PH 9.0x you have both Balanced and unbalanced outputs available, as balanced outputs come standard with the 9.0x (a $300 upcharge with the 9.0).
The sonic benefits of this circuit change are obvious and significant. There is better bottom end, more weight and authority to the sound as well as improved resolution, detail and soundstage.
The PH 9.0 X adds takes the reference performance of the PH 150 tube phono stage to a level of performance that belies its affordable price.
Why Is The Balanced Option So Much More Expensive?
Balanced outputs are automatically possible because the output of the transformer is now a fully balanced signal. The RCA outs are also fed from this same transformer however, but obviously not balanced. This means that a toggle switch is needed to toggle from RCA to XLR outs. If you connect RCA outs when the toggle is in the XLR position, it will sound wrong because the grounding is not right for single-ended operation.
Both RCA and XLR outputs should both sound the same. It really depends on whether the preamp or integrated amp that you are connected the PH 9.0 to, prefers a balanced or single ended (RCA) connection.
This is different than our $300 XLR balanced upgrade for the standard PH 9.0, which simply adds a pair of 1:1 Edcor transformers to the existing circuit, to provide a balanced output. Only the balanced signal goes through the transformers in this case. The ‘X’ upgrade is a redesign, not just an addition of transformer coupled balanced XLR’s.
The Modwright PH 9.0 retains the flexible MC cartridge loading and gain adjustment of the PH 150 and utilizes similar circuitry. However, the PH 9,0 is in a smaller enclosure that allows for greater flexibility in placement. The 10″ x 10″ x 4″ external power supply can be hidden and 6ft umbilical allow for ease of setup and placement.
Modwright also chose wisely in implementing Lundahl MC step-up transformers, and separate MM and MC inputs. The use of external supply, careful grounding, layout and solid engineering result in an extremely quiet tube phono stage.
The PH 9.0 uses the same (2) 6C45 and (2) 6922 tube complement of the PH 150 and embodies the same tonality, soundstage and musical presentation. Max MC and MM gain of 64dB and 52dB respectively, as well as 0dB, -6dB and -12dB gain adjustment, accommodate a broad range of MM and MC cartridges.
The back panel features one set each, MM and MC RCA inputs and one set of RCA main outs. The PH 9.0 can be fitted with (at an additional cost) fully balanced, transformer coupled XLR main outs. Turntables with two tone arms are easily accommodated, and with an outboard step-up transformer for the MM input, two MC cartridges may also be used.
“There is some real enchantment in the midrange here, as it seems to effortlessly and fluently present that inescapably correct body and bloom one ultimately expects from a good valve preamplifier. Authority through the so-called power range (J. Gordon Holt’s, The Audio Glossary, claims that range to be 200Hz to 800Hz, or from the very upper bass regions into the middle midrange realm), is remarkably solid and exceptionally well-controlled. Its ability to render accurate tonal color and to capture the vibrance and texture of voices while maintaining a remarkable level of resolve and transparency may be unprecedented at this price, and is not markedly dissimilar to the remarkably lofty performance of the PH 150 Ref.” – Greg Weaver, Positive Feedback
PH 9.0 Specifications
- MC Gain: 64dB (58dB, 52dB)
- MM Gain: 52dB (46dB, 40dB)
- Gain Adjust: 0, -6dB, -12dB
- Inputs: MM & MC
- MC Loading: 10-20-50-100-250-470
- MM Loading: 47K fixed.
- Stereo/Mono: Rear Toggle.
- Frequency: 20Hz – 50Khz (+/-.2dB)
- Tubes: (2)6C45, (2)6922/6dj8/7308
- Power Supply: External, solid state
- Phono Dim = 10“Wx10“Dx4“H
- Power Supply Dim = 7“Wx9“Dx3“H
- Power Umbilical: 4-pin XLR, 6 ft
- Balanced Outs: Transformer Coupled (add cost option)