As much as I adore the input attenuator, as much do I worry about the complex resistor network. This means losses at high frequencies.
Ortofon has to a degree met this by the decoupling of the k resistor with C1. Factory adjusted But Before The Match - Various - All To Nah (Vinyl) would rather dump the whole thing and do with a single high quality pot or att.
But we do not need that much gain for domestic use. It is probably advisable to remove it, although also a little sad. It was an expensive device back then…. Still is…. The AcroSound company was founded by Hafler and Keroes. Apart from their good transformers, the company produced some really nice amplifiers. This amplifier is most likely the best designed by Acrosound.
I have now edited the schematic and filled in the values of the Before The Match - Various - All To Nah (Vinyl) as well as the DC voltages. Nice — really nice…It differs from the traditional Williamson in that the power tubes are driven by a cathode follower and that it uses active bias. The 12AY7 is a good choice for the input tube. But I am not Before The Match - Various - All To Nah (Vinyl) happy about the low voltage presented to the two triode parts of the 12AY7.
Care should be taken to find the proper bias point for the second triode. But some further 70 Volts or so, to both of these triodes will provide wonders. I would also decrease the input plate resistor and go for a higher bias point at the input triode. Higher bias here is more headroom. I think it is possible to double the bias to about 2Vdue to an increase of the plate voltage to about V and a plate current close to 2mA.
All in all this will also place the two triodes in a more linear area of the plate characteristics, which spells lower distortion. The 5nF coupling capacitor is a little too low for modern high quality full freq HiFi.
Too large capacitors affects the pulse and HF merits, due to the DC recovery. Do also note that the PSU is a choke input type. This demands a choke capable of handling the excessive AC Voltages, but provides considerable better regulation and lower ripples than a regular CLC. The overall gain high for modern use, though. I always use such resistors and strongly recommend this as a common practice.
Apart from providing a neat measuring point, such resistance slightly improves the linearity due to cathode regeneration and further adds some protection against runaway. There is a few things I would like to add here, now that I have a second run at this schematic. The bias arrangement does not provide any DC or AC balance. I think I would prefer a balancing potentiometer at the cathodes of the 6SN7 cathode follower or alternatively two individual bias adjustments for each grid. By placing the pot as the sole voltage divider, responsible for the bias voltage it is possible to accidently turn the whole thing into self destruction — further it is quite difficult to find the proper point as the pot cover a very wide range: 0V to V.
The simple and efficient solution is to add one or two resistors, like this:. Fig1shows the two extra resistors. Strictly speaking only R1 is necessary, but R2 will allow ease and precision of adjustment. The smaller the voltage span the potentiometer needs to cover the better are we capable of adjusting it. The voltage across the 6SN7 plate to cathode is V. The current drawn can be calculated via the informations in Fig. Anyway — by looking at the plate characteristics for 6SN7, we find that at Volts and 4,8mA, the bias is about V.
If we covers an area of about V to Vwe are on the safe side — by quite a margin. That means we draw 1mA through the resistors from the Volts to ground.
If we make R1 into a 10k, we insure that we can never adjust below V. If we then make the potentiometer into 22k, we can adjust from V to V. We do not need any precision here We adjust for the precision neededthis means that any standard resistor value is perfectly alright.
The potentiometer could be anything from about 18 to 27k. R2 could be k. Another little tip — the lower the resistance of the bias network the better the stability. But as we make them lower, they draw more current, hence increasing ripple. If we cut the total values into half of the above, we would end at 67,5k and we would draw a total of 2mA.
We would still be on the good side. The 22uF electrolytic could be swapped into 47uF. The final note I would like to make is that I personally never use half wave rectifiers. I would prefer a bridge any day in order to improve regulation and allow a higher electrolytic, possible even a CRC filter. Capacitor — resistor — capacitor. But that is just this viking speaking. This is yet another adorable power amplifier from the labs of Altec.
It is a Williamson design again! Hence the choke load. The rest of the amplifier is pretty conventional, although of good and intelligent engineering. It is clearly made for high power and continuous use. The Voltage for the driver amplifier is taken from a separate winding, using a Voltage doubler. The R resistor in the current loop provides the negative bias of V, by means of the grounding technique. The total gain of the amplifier is about 72 db.
This sounds like a lot, but it has to be seen in the light of the output of close to W. The input sensitivity fits a modern signal source very well. It came with an optional input transformer. Noise Level: Output noise dbm: 77 db below rated output. As far as I can tell this Altec had no fuse. Instead it is equipped with a thermal bimetal circuit breaker.
This has the advantage that in case of overheating the 5 Ohm resistor would be in series with the power transformer and the amplifier would keep on playing, although at lower level.
It was mounted with an interlock switch as well, in case someone would try to tamper with it with the power on. The Williamson input stage is DC-coupled, which often means a relative low plate Voltage for first tube. This goes for the as well. The plate resistor of k makes that lazy 12AX7 more sleepy than it has to be. It would make good sense from a sonic point of view to change it toor 12AY7. The k should be divided, so that only some k loads the input.
Remember to insure that the phase splitter second stageare strapped to fit the plate Voltage for bias! The 6SN7 makes a fine differential amplifier, but you may consider to strap it with a long tail or CCS at the cathodes. You might also consider to change the k plate resistors to a more reasonable 47k or so, for a higher roll off. Better pulse response.
The driver is fine as it is, no need to change anything here. Due to the nature of the and the circuit as such is is not possible to adjust this amplifier into AB — not even AB2. I do not know how much current the power transformer may deliver at continuous service I have no at handbut it looks like it might be capable of some mA? Now THAT would make this amplifier a true monster with regards to sound as well. These are not quite the same asbut might be an even better solution in this circuit.
In both cases adjust the bias for class AB2, that will ease the continuous current demand and still allow some W class A. By using a separater transformer for the filament, we will lift some 50 Watts of burden off the shoulders of the mains transformer. I think it is a plausible modification.
The PSU is a nice choke loaded breed, which insures good regulation. The Voltage drop over these are quite dramatic, in particular for a class B amplifier. This will compress the signal. That might not be a bad thing for many public address applications, but it will modulate the signal as well and that is never good.
The small 6uF paper in oil capacitor wont be of much help here. The plate to plate copper resistance of the OPT is quite low — only 96 Ohms. This is in particular low considering the relative high impedance of Ohms. Nice job, Peerless. Variable feedback damping. Stunning good engineering. There is always a funny and original detail or two to be found in these amplifiers. AMPEX Early Perhaps the first Ampex monitor amplifier, ca.
Ampex was founded a while after WW2, probablyas a manufacturer of reel to reel tape recording and player machines. The company was the joined forces of Russian Alex. Germany was miles ahead of every one else with regards to high quality audio magnetic tape machines. The system was adapted by RCA and several other major companies.
It was introduced worldwide in and many license agreements was issued. The relative recent development of high quality magnetic tape recorders and magnetic tape in Germany made it possible to control the recording process. Presto, Rek-A-Cut and similar companies never reached any significant sonic quality to the best of my knowledge. Only one channel shownwithout power supply. See Stephie Bench 4 I suggest to go for current or power drive. Looks good to me…. It really looks wonderful.
And the text is in Dutch of which I am not too good Anyway — the stage works properly as madebut most likely leaves a little room for improvementnot least with regards to headroom. Bias The input of the input transformer is shorted via relay 2 during heat up. EL Power Supply. The power supply is a story of its own. The choke is again placed in the ground side in order to avoid high voltage potential differences from the entire choke system windingscore and enclosure if such is used Lets have a closer look at these impressive mercury rectifiers.
A cool feature of mercury rectifiers is the purple neon glow. This model was referred to as ELS. This is definitely a circuit worth for experiments. Read vignette and schematic at Fisher 50A in part 1. Good pick. Sadly he got killed during this task The first two stages in the V40 is a cascade of the two high gain sections of ECC The parallel combination of the 2M2 and 50p from plate to grid is yet another HF cancellation!
A word of warning. Hats off to EL84 and its remote cousin PL Excellent pentodes for audio. All in all a very nice amplifier, with little need for improvements.
The Klangfilm V is admirable good audio engineering. Hats off guys…. Still isby the way Before The Match - Various - All To Nah (Vinyl) input pentode is a special quality type E80F supplied with gold pins. All in all a very good engineered amplifier. Excellent design. The simple and efficient solution is to add one or two resistors, like this: Fig1shows the two extra resistors. Weight: 59 lbs The Williamson input stage is DC-coupled, which often means a relative low plate Voltage for first tube.
Better pulse response The driver is fine as it is, no need to change anything here. When deciding on the singer for the game's theme song a manager brought the team one of RIKKI 's albums, and after just one listen, they unanimously decided she was the only singer they wanted. Uematsu called the album is a masterpiece, and Rikki's voice "amazing", which made him choose her.
Uematsu went about composing the music for Final Fantasy X by setting up a synthesizer in his office at night. At one point he turned out 15 songs in an hour, one of which ended up being the theme song.
Uematsu rates "Suteki da Ne" as his favorite from the album, followed by the opening theme. In an interview prior to the release of Final Fantasy XUematsu stated the game would feature approximately 70 tracks of music, however, the game's final soundtrack actually includes just over 90 tracks. The sound team, Uematsu included, only started testing the game in the latter half of development, which is when they found out how the game designers had used their music.
I realized that the FF series has already gone into its 10th installment! If I think back 14 years from now, way back inthat was the day FF1 was first announced. I started producing for the game when I was about 27 years old, now I'm almost Life is long, and I'm not young anymore. I remember back during my Junior High school days, embracing my favorite popstar idols such as Elton John, Paul McCartney etc, it was a time of being carefree. As I grew out of that stage of my life, I sort of lost touch with their music.
Recently, as planned, I started to listen to the music of these great artistes again, calmly all alone by myself. I went to compare my own works with the music of my idols as a measure of the level of 'accomplishment' my works have reached. For my case, there are some which are great and some that are not so, but ALL my idols' works are just brilliant and not a single one that sounds blemished. I feel that the best music comes from the hippy era of the 70s where people expressed themselves fully through the sound of music.
But on a previous occasion while I was driving in my car, I was tuning the bass level of a particular song, and realized the other fine nuances of other instruments that made up that song.
This song is sheer genius! I said to myself, shocked at the accidental discovery. I went on to experiment the same procedure with Before The Match - Various - All To Nah (Vinyl) of other artistes, muting off the piano rhythm, it's easy to mistake the music progression.
I tried this again CD after CD, weaning out those great works apart from the bad ones. It really has become my latest obsession, really. You can pick up traces where the artistes were not prepared enough and were not in the right mind to perform or sing.
These 'evidences' is recorded down forever. Of course, popstars are human too. But I do feel a little sad that these so-called idols of my past whom I thought were perfect, actually faltered.
As if I was God high up in the sky, calmly and rationally judging these artistes' failures. The operation of the variable valve lift system may be summarised as follows: At engine speeds below rpm, valve lift for one of the intake valves was reduced to increase intake air speed and to create a swirl effect within the combustion chamber since the lift of the two intake valves differed.
As a result of the faster intake air speed and better mixture formation, a higher torque output was achieved; At engine speeds between rpm and with high loads, valve lift for the variable intake valve would be increased to reduce intake resistance for greater power; and, At engine speeds above rpm, high valve lift would be provided regardless of load.
Injection and ignition. Article by Ian Lithgow. Of course you would! Like I mentioned previously, before my WorkBox 3. I could hardly remember what I had, and if I actually happened to, there was a slim chance that I could locate it before just giving up the search and heading to the craft store…hello wasted money! I became pregnant right after we moved in last year, and the house took a backseat thanks to morning sickness and then life with a newborn. So long, card table and plastic tubs!
Just use this link. Thanks so much for stopping by! I just could not figure it out. I thought, my word it can't be that difficult. You saved the day!! Thank you!!!! Thank you for such an honest review! We are moving and I am losing my current craft room. I had looked at these years ago but the price stopped me. I actually had a "craft closet" built into the bedroom closet instead.
I totally would not accept the damages or other issues paint color, plastic containers cracked. I now believe when we move I will probably have to "rebuild" something into the new closet. You have saved ME time, money and lots of stress. My Matt does not mind helping put things together, but would have been aghast at all the bad work and cheap materials.
I would expect a discount for all the broken stuff on the "new" item. If it was used, I would expect the chips in the looked like particle board? My husbands wood working for anything would not be accepted by anyone if it looked like that. Thanks for the review. I think that I will have my handyman make me one to my specifications.
I have a sewing machine, embroidery machine, Cricut machine and a large easy press. I have different space needs. I'm happy you are enjoying your box! Happy Crafting. I just came across your article. You are lucky that you have the same bins that the DreamBox has. I obviously purchased my WorkBox before you did because my bins are flimsy.
I contacted the company today to try an upgrade my doors because the plastic totes are a joke!
I Can Prove It - Various - Super Disco (Vinyl, LP), Adagio E Staccato - Hændel*, Bach* - Vivaldi* / Jeanne Demessieux / Orchestre De La Suisse Romande*, Come Up (remix) - Down South Criminalz - In Da Park (CDr), Como Antes - Los 4 Hermanos Silva - Boleros y Folklore (Vinyl, LP, Album), You Belong To Me (Theme) - Lords Of Acid - Our Little Secret (Special Remastered Band Edition) (Viny, Rock Me Baby - The Wild Goners - Face The Space (Vinyl, LP), Jigsaw - Marillion - Fugazi (Vinyl, LP, Album), Adam West (2) - In The Back Of My Hearse (Vinyl), Learning To Let Go, I Killed My Horse This Mornin - Dan Crall - North (CDr, Album), Bomb - Tuk Tuk Rally - Erbanaza! (CD), Comes And Goes - Dan Fogelberg - Captured Angel (Vinyl, LP, Album), Past & Present (Jazz-n-Groove Mix) - Various - DJs Take Control - Volume 3 (CD), You’re Mine - Various - Soul For Dancers 2 (Out On The Floor Firecrackers) (Vinyl, LP)